AITOFF [L B] - converts L-b coordinate values to equivalent x-y positions.
	AITOFF will convert the X values (longitude) from the most recent
	XCOLUMN command and the Y values (latitude) from the most recent
	YCOLUMN command and convert them to the equivalent x-y positions for
	use in an Aitoff (more precisely, a Hammer) projection.  The AITOFF
	command MUST be called every time new data is inserted either with the
	XCOLUMN or YCOLUMN commands.  If the optional arguments L and B are
	present, they are converted to the equivalent x-y positions for use in
	an Aitoff projection.  For the equivalent Aitoff "box", see the GLOBE
	command.
ANGLE D or ANGLE X1 X2 Y1 Y2 - sets angle of text or points to D degrees.
	ANGLE will cause text from LABEL and PUTLABEL commands to be presented
	at D degrees counterclockwise from the horizontal (+x direction).
	Alternatively, if there are four arguments present, then they are
	taken to be the World (user) coordinates of two positions and the
	ANGLE is set to the slope of the line.
ARC MAJX MAJY [ANG [STARTANG]] - draws an arc with major axes MAJX, MAJY.
	ARC draws an arc at the current cursor position with major axes MAJX
	and MAJY (in World coordinate units).  The curve is drawn as a polygon
	with the characteristics specified by the command FILL.  The number of
	points used to generate the curve can be controlled by adjusting the
	value of the character expansion (see the command EXPAND).  The
	optional parameter ANG defines the angular extent of the arc in
	degrees (set to 360 degrees if not given).  An additional optional
	parameter, STARTANG, may be used to determine an initial offset angle
	of the arc relative to MAJX (this defaults to 0 degrees if this
	parameter is not present).  Use the command ANGLE to set the rotation
	of MAJX with respect to the positive x-axis.  All angles are in units
	of degrees and are defined to be zero toward the right of the viewport
	(regardless of the direction of the World Coordinate system) and
	increasing counter-clockwise.  See also the BEAM command.  NOTE: If
	the World Coordinate system is currently RA and DEC, a rotated arc may
	not plot correctly.  Use 'header px px' or 'header so so' (or some
	other equivalent offset option) to set the coordinate system to
	something comparable in scale.
ARROW X Y [ANGLE [VENT]] - Draws an arrow.
	ARROW draws an arrow from the current cursor position to the World
	(user) coordinate (X,Y).  The acute angle of the arrow point, in
	degrees, is specified by the optional input ANGLE; angles in the range
	20.0 to 90.0 give reasonable results.  If ANGLE is not present on the
	command line, a value of 45.0 degrees is used.  The fraction of the
	triangular arrow-head that is cut away from the back is specified by
	the optional parameter VENT.  A value of 0.0 gives a triangular wedge
	arrow-head; 1.0 gives an open >.  Values of 0.3 to 0.7 give reasonable
	results.  The default value for VENT (if it is not present) is 0.3.
	EXPAND can be used to vary the length of the arrowhead.  For EXPAND
	set to 1.0, the default size of the arrowhead is 1/40th of the smaller
	of the width or height of the view surface.
ASK K - Changes the current device prompt state.
	The command ASK will set the prompt state to ON if K is set to 1 and
	the current device selected is interactive; otherwise, ASK will set
	the prompt state to OFF.  If ASK is set ON, then every command that
	erases the page will prompt the user before clearing the screen.  The
	default state of this is OFF; also, every time a new device is
	selected (see DEVICE), ASK is set to OFF.
AUTOLEVS NLEV [TYPE [MIN [MAX]]] - sets up the contour levels automatically.
	AUTOLEVS will fill an internal contour level array with NLEV contours
	between the values MIN and MAX.  NLEV must be input, but the rest of
	the parameters are optional.  If either of or both MIN and MAX are not
	given, they are default to the minimum and maximum of the current
	array loaded using the command IMAGE.  The optional parameter TYPE is
	a string of characters specifying the type of contour levels to
	generate.  If TYPE is LIN, then the contour levels are linearly spaced
	(this is the default if TYPE is not present); if TYPE is LOG, then the
	levels are spaced evenly in the logarithm.
BAR K [THRESH [GAP]] - draws bar graphs on (x,y) pairs in direction 90(K-1).
	BAR is analogous to the command BIN except that it will draw a bar
	graph on all (x,y) coordinates read by XCOLUMN and YCOLUMN in the
	direction specified by the argument K.  Set the argument K to 1 to put
	the bar extending towards the +X direction; 2 for +Y; 3 for -X; and 4
	for -Y.  The values read by the most recent call to ECOLUMN determine
	which color to draw individual bars.  If this array is empty, the
	current color index is used.  The optional argument THRESH may be used
	to specify the "bottom" of the bar.  If this optional argument is
	present, then it is used to anchor the beginning of the bar graph and
	should be entered in the units of that axis.  If this optional
	argument is not present, the box edge opposite the direction the bar
	extends acts as the threshold.  An additional optional argument GAP
	may be used to specify the "width" of the bar.  If this is not
	present, the width is defined as the difference between the mean of
	the current point and the next point and the mean of the current point
	and the previous point.  If GAP is present, it should be in entered in
	units of that axis (i.e.  for K == 2, GAP should be in the units of
	the X-axis) and the bar will be centered on the point with half the
	width on either side.
BEAM MAJ MIN PA [OFFX OFFY [SCALE [FILLCOLOR [BGRECT]]]] - draws a beam.
	BEAM draws a beam at the current cursor position outlined using the
	current color and line width properties.  It has a major axis MAJ and
	minor axis MIN and is rotated by a position angle PA (which is in
	units of degrees defined as zero along the positive Y-axis (regardless
	of the current World Coordinate system) and increasing
	counter-clockwise).  The optional parameters OFFX and OFFY (which both
	default to 0) define the offset of the center of the beam from the
	current cursor position.  These offsets are in units of the width or
	height of the box that bounds the beam.  The beam will first be drawn
	solid using the optional input FILLCOLOR and is then drawn hollow with
	the current color.  If FILLCOLOR is not provided, it defaults to color
	index 15.  By default, the axes will be scaled as if header rd rd has
	been previously called.  This means that the X-axis will be scaled by
	15*cos(declination).  To override this scaling, the optional input
	SCALE can be provided and set to whatever scaling is desired (no
	scaling can be achieved by setting SCALE to 1).  If SCALE is set to
	any negative value (or is not present), then RA-Dec type scaling will
	be done.  The major and minor axes of the beam should be in the same
	units as the two axes.  This means if SCALE is set to anything but 1,
	then they should both be in the same units as the Y-axis.  If the
	optional argument BGRECT is provided (it defaults to 0) and is not
	negative, then a solid rectangle will be drawn in that color (color
	index BGRECT) first.  The rectangle will only be as large as the width
	and height of the beam.
BGCI N - sets the text background color index to N.
	BGCI sets the text background color index for subsequent text.  By
	default, text does not obscure underlying graphics.  If the text
	background color index is positive, however, text is opaque:  the
	bounding box of the text is filled with the color specified by the
	value of N before drawing the text characters.  Use color index 0 to
	erase underlying graphics before drawing text.  If N is less than 0,
	the text will be transparent; if greater than or equal to 0, the text
	will be drawn on an opaque background with color index N.  The initial
	value of the text background color index is -1 (transparent) and is
	reset to -1 whenever a new device is selected.
BIN [K [GAP] ] - draws a histogram of (x,y) pairs.
	BIN connects the coordinates read by XCOLUMN and YCOLUMN as a
	histogram.  If the optional argument K is present and equal to 0, then
	the individual X values denote the lower left edge (in X) of the bin.
	If K is set to 1 or is not present, then the individual X values
	denote the center location of the bin.  If the optional parameter GAP
	is present, it represents the distance (in X axis units) that signals
	a gap in the histogram not to be connected.  This is useful for
	histograms with irregular spacing or directional changes.  A good
	value for GAP is 2.
BOX [x [y] ] - makes a box labeled according to LIMITS and TICKSIZE.
	BOX annotates the viewport with a frame, axes, numeric labels, etc.
	The two arguments X and Y are strings of options that determine the
	type of box and the labeling that will be drawn.  The option letters
	may be in any order and do not depend on case.  If either parameter is
	omitted, the missing parameter is given the default value set by the
	string variables XBOX and YBOX (see the command SET).  If none of the
	letters `A', `B', or `C' are specified, then tick marks will not be
	drawn.  The options currently available are:
	  A : Draw Axis line (X axis is a horizontal line at Y=0, Y axis
	      is a vertical line at X=0).
	  B : Draw Bottom (X) or Left (Y) edge of the frame.
	  C : Draw Top (X) or Right (Y) edge of the frame.
	  D : Include the superscript symbols 'o', ''', and '"'.
	      If this option is used, the option `Y' is implicitly implied.
	  F : Write only the last part of the label for the first time
	      (left or bottom most) tick on the axis (see Z).  For example,
	      if the full first label is 17 42 34.4, then only write 34.4.
	      This option is useful for sub-panels that join each other.
	      Care is needed because first label carries sign as well.
	  G : Draw a Grid of vertical (X) or horizontal (Y) lines at each of
	      the major tick mark positions.
	  H : Include the superscript symbols 'd', 'h', 'm', and 's'.
	  I : Invert the tick marks; i.e. draw them outside the viewport
	      instead of on the inside.
	  L : Label axis Logarithmically.  If option `Z' is used, then this
	      option is ignored.  The major tick interval is ALWAYS 1.0;
	      the number of minor ticks is ALWAYS 8.  The numeric label is
	      10**(x) where x is the world coordinate at the tick mark.
	  M : Write Numeric labels in the unconventional location Above (X)
	      or to the Right (Y) of the viewport.
	  N : Write Numeric labels in the conventional location Below (X)
	      or to the Left (Y) of the viewport.
	  O : Omit leading zeros in numbers < 10 in time labels.  For
	      example, the label 3h 3m 1.2s will be written rather than
	      03h 03m 01.2s.  The day field is not affected by this option
	      and this option is ignored unless used with the `Z' option.
	      This option is ignored when used with the `V' option as it
	      makes it impossible to align the labels nicely.  This option
	      is useful to help save space on the X-axis.
	  P : Extend ("Project") the major tick marks outside the box.  This
	      option will be ignored if option `I' is also specified.
	  S : Draw Minor Tick marks (Subticks).
	  T : Draw Major Tick marks at the major coordinate interval.
	  V : Orient numeric labels Vertically.  This is only applicable
	      to the Y axis.  The default is to write the Y-labels parallel
	      to the axis.
	  Y : Do not include the day field in time labeling.  This means
	      that labels are "HH MM SS.S" rather than "DD HH MM SS.S".
	      The hours will accumulate beyond 24, if necessary, in this case.
	  Z : Use time labeling ((DD) HH MM SS style).  The World
	      coordinates of the box (see LIMITS) and the tick mark increments
	      (see TICKSIZE) should be given in units of seconds.
	  1 : Force decimal labeling, instead of automatic choice.
	  2 : Force exponential labeling, instead of automatic.
	  0 : By itself, a zero produces a null operation argument; useful
	      to produce a box along only one axis.
BUFFER - predefined macro name that refers to the entire command buffer.
	Typing BUFFER will execute the contents of the command buffer (the
	same as the command "playback" or "playback buffer").  BUFFER may also
	be used as an argument for commands requiring a macro name (e.g.  LIST
	and WRITE).
COLOR N - select color for lines and characters.
	COLOR defines the current color index used for filling polygons,
	drawing lines, and labeling characters for the selected device.  COLOR
	is originally set to 1 and is reset to this value whenever a new
	device is selected.  The number of colors available is device
	dependent (the range can be displayed with the command 'echo cmin
	cmax').  If the requested color index is not available on the selected
	device, a color index 1 will be substituted.  The first 16 colors
	usually have predefined values.  Additional values are device
	dependent.  Each color associated with the color index N is listed in
	the following table:
	   n    Color                     n     Color
	--------------------------------------------------------------
	   0    Black (background)        8     Orange (Red + Yellow)
	   1    White (foreground)        9     Green + Yellow
	   2    Red                      10     Green + Cyan
	   3    Green                    11     Blue + Cyan
	   4    Blue                     12     Blue + Magenta
	   5    Cyan (Blue + Green)      13     Red + Magenta
	   6    Magenta (Red + Blue)     14     Dark Gray
	   7    Yellow (Red + Green)     15     Light Gray
	                                 16-255 Undefined
CONNECT - connects (x,y) pairs with line segments.
	CONNECT draws line segments connecting the coordinates read by XCOLUMN
	and YCOLUMN.  The lines are drawn using the current line style (set by
	the command LSTYLE), in the current color (set by the command COLOR),
	and the current thickness (set by the command LWIDTH).
CONTOUR [N [BLANK [MIN]]] - makes a contour plot of an array read with IMAGE.
	CONTOUR makes a contour plot of an array read with the IMAGE command
	at the contour levels set using either the LEVELS or AUTOLEVS
	commands.  The contour levels MUST be set before a call to CONTOUR.
	The contour level array will be modified according to the current
	value of the user variable SLEVEL and the string variable LEVTYPE
	(also see the command SLEVEL) before calling any of the contour
	methods below.
	Currently, there are four contour routines available.  The optional
	parameter N allows the user to select which of four contour drawing
	methods will be used to generate the plot.  If N is the character `s',
	then the command will produce a fast contour plot (this is the default
	if N is not present); if N is `t', then a smoother contour is
	produced; if N is `b', then the same contour plot as with `s' is
	produced but with blanking; and `l' produces the same contour plot as
	with `t', but with contour level labeling.
	For N set to `b', an optional argument BLANK may be given to specify
	the blanking value such that array elements equal in value to BLANK
	are ignored (blanked).  For N set to `l', the optional argument BLANK
	defines the spacing along the contour between labels (in grid cells)
	and the optional parameter MIN specifies the minimum number of cells
	that must be crossed before drawing the first contour label.  The
	default value for BLANK is 0.0 when N = `b' and 16 for N = `l'; MIN
	defaults to 8.  The optional parameters are ignored by the contour
	options N = `s' and `t'.
	By default, each contour line is drawn with the current line
	attributes (color index, line style, and line width).  However, for
	options `t' and `l', the default is to draw negative contours values
	with dashed and positive contours values with solid lines.  If,
	however, the parameter N is set to `-t' (option `t' prepended with a
	minus sign), then negative contours values will be drawn with the same
	line style as positive contours values.
CURSOR [x y] - enables cursor and returns x-y location and the key pressed.
	CURSOR enables the graphics cursor and returns the x-y position of the
	cursor along with the key pressed.  CURSOR may also display the image
	value of the selected position if an array is currently loaded (see
	the IMAGE command) and the cursor position lies within the scope of
	the image region (see the command TRANSFER).  The two optional
	arguments may be used to determine the starting position of the
	cursor.  If both parameters are given, they are used as the World
	(user) coordinates for the starting position.  If only one parameter
	is present, it is used as the X starting position and the Y position
	is set as the current cursor position.  Finally, if no arguments are
	present, the current cursor position is used as a starting position.
	If CURSOR is called inside a macro (see the command DEFINE), with the
	command PLAYBACK, or is executed inside a file via the command INPUT,
	then only one keystroke is allowed and no saving of commands will be
	done.  If, on the other hand, CURSOR is called interactively, then
	CURSOR may perform several functions, depending on the character
	typed.  Internal calls to CURSOR will occur repetitively until the
	letter `X' is typed.  On some devices, the left most mouse button will
	be associated with the keystroke `A'; the middle with `D'; and the
	right with `X'.
	Other keystroke functions are:
	    A : Display the cursor position and image intensity.
	    D : Draw to the current cursor position.
	    M : Move to the present cursor position.
	    P : Draw a point of the current symbol type.
	    S : Toggles ability to save following keys as commands.
	    X : Exit the cursor routine.
	    ? : Present this list of key commands.
DATA fspec - opens the file "fspec" for reading data.
	DATA opens an external file for reading data.  The file is assumed to
	have data in columns separated by spaces, tabs or commas.  Any column
	can be read as x or y coordinates with the XCOLUMN and YCOLUMN
	commands.
DEFINE xxx - creates the macro xxx and enters define mode.
	DEFINE creates an entry for the macro xxx, and subsequent commands
	(until the END command) are considered the body of the macro.  The
	prompt changes to DEFINE> to indicate the mode.  A macro is just a
	collection of commands (or other macros) that can be executed with one
	call statement.  A macro is invoked by using its name as a command.
	The contents of the macro may be listed by using the macro name as an
	argument to the command LIST.  Macros may be saved using the command
	WRITE and may be played back using the command PLAYBACK.  Macros may
	be passed arguments or variables whenever they are executed.  The ten
	tokens used inside the macro to identify the macro arguments are $1,
	$2, ..., $9, and $0.  These tokens may be used in the body of the
	macro, and when the macro is invoked its arguments will be substituted
	for these tokens.  These tokens MAY NOT be redefined inside the macro
	(for example, using the command SET).  If an argument is not present
	when the macro is invoked, the token is replaced with a blank space.
DELETE [N1 [N2 [MACRO]]] - removes the commands N1 - N2 from a macro buffer.
	DELETE removes commands from the macro listing (numbered according to
	what is shown with the command LIST).  If no arguments are present,
	then the last command in the command buffer (see BUFFER) is deleted.
	If N2 is not present, then only the command numbered N1 in the command
	buffer (BUFFER) is removed.  If both N1 and N2 are present, then all
	commands from N1 to N2 (inclusive) are deleted from the command buffer
	(BUFFER).  If the optional macro name is given, then lines N1 to N2
	(inclusive) are removed from MACRO.  For example, to remove line 4
	from a macro named "dojob", use the command delete 4 4 dojob.  Note
	that the command buffer macro name is "BUFFER".
DEVICE device - initializes output to a graphics device.
	DEVICE defines the "device specification" for the plot device.  The
	specification is system dependent, but usually has the form
	"device/type" or "file/type".  If the argument is a question mark
	("?"), the user will be prompted to supply a device name after a list
	of the currently available devices is presented.  When a new device is
	selected, the PANEL command is reset and the COLOR, EXPAND, FILL,
	FONT, LSTYLE, and LWIDTH commands are called to reset each to a value
	of 1.  The color palette (see the command PALETTE) is also reset to
	the default palette and the coordinate transfer function (TRANSFER) is
	reset to linear.  Finally, the inquire state is turned off (see the
	command ASK).
DOT [X Y] - makes a point of the current style at the current location.
	DOT draws a point at the current location (set by MOVE, DRAW, etc.)
	(or at the position (X,Y) if provided) in the style determined by the
	latest call to SYMBOL or PCOLUMN.  The symbol's size is governed by
	the last call to the command EXPAND.
DRAW X Y - draws a line to (X,Y) from the current coordinate position.
	DRAW draws a line to the World (user) coordinate (X,Y) from the
	current location (set by a previous call to MOVE, DRAW, etc.).  DRAW
	then makes (X,Y) the current position.
ECHO EXPRESSION [...] - displays the result of EXPRESSION on the screen.
	ECHO acts just like the command SET except that rather than assigning
	the result of the EXPRESSION to anything it displays the result on the
	screen.  See the command SET for an explanation of EXPRESSION.  There
	may be more than one EXPRESSION present, but each one should be
	delimited by enclosing parenthesis.  Literal strings may also be
	displayed by enclosing the text in double quotes.  String variables
	may be displayed by listing their names.  For example, to display the
	current cursor position, use the command:  echo "cx = " cx "cy = "
	cy.
ECOLUMN N - reads error bar data from column N of the data file.
	ECOLUMN reads column N from the data file as the magnitudes of the
	error bar displacements from the corresponding (x,y) coordinates.
	Note that the command LOGARITHM does not adjust the error values to
	logarithmic scale.  ECOLUMN values are also used by the command
	LOOKUP.
END - terminates define mode, insert mode, or exits from the program.
	In DEFINE mode, END finishes the macro definition and returns to
	EXECUTE mode.  In INSERT mode, END terminates inserting and returns to
	EXECUTE mode.  In EXECUTE mode, END exits from the program
	altogether.  The commands EXIT and QUIT may be used as a substitute
	for the command END.
ENVIRONMENT [X1 X2 Y1 Y2 [N [K]]] - sets the user limits and draws a box.
	ENVIRONMENT can clear the current page, set up the World (user) limits
	and draw a standard box.  The first four optional arguments establish
	the World (user) limits of the plot region.  If they are not present,
	then the data read from the most recent call to the commands XCOLUMN
	and YCOLUMN is used to autoscale the limits.  If the limits are
	present, then two other optional parameters may be selected.  The
	first of these parameters, N, will set the scales of the X and Y axes
	to be equal, if it is equal to 1; otherwise the two axes will be
	scaled independently.  The final optional parameter K will determine
	what type of box to draw and may have the following values:
	    -2 : draw no box, axes or labels;
	    -1 : draw box only;
	     0 : draw box and label it with coordinates;
	     1 : same as K=0, but also draw the coordinate axes (X=0, Y=0);
	     2 : same as K=1, but also draw grid lines at the major
	       : increments of the coordinates;
	    10 : draw box and label X-axis logarithmically;
	    20 : draw box and label Y-axis logarithmically;
	    30 : draw box and label both axes logarithmically.
	Both N and K default to 0 if not provided.
ERASE - erases the graphics screen.
	ERASE erases the graphics screen.  If the current device is a hardcopy
	device, ERASE will cause the plot to advance to the next page.  If ASK
	is set ON and the current device is not a hardcopy device, then the
	user will be prompted before advancing to the next page.
ERRORBAR K - draws error bars on (x,y) pairs in the direction 90(K-1).
	ERRORBAR is analogous to POINTS; it draws error bars at each of the
	(x,y) points (read by the most recent call to the commands XCOLUMN and
	YCOLUMN) at a length specified by the points read by the command
	ECOLUMN.  The argument K should be 1 to put the bar along the +x
	direction; 2 for +y; 3 for -x; and 4 for -y.  If K is 5, then error
	bars are drawn in both the +x and -x directions.  Likewise, if K is 6,
	then error bars are drawn in both the +y and -y directions.  Use
	EXPAND to govern the size (extent) of the caps.  Setting the expansion
	to zero means no caps are drawn.
ETXT - erases the text from the view surface without affecting graphics.
	ETXT erases the text from the view surface (if the device is capable
	of doing this).  This should erase text without affecting the
	currently displayed graphics.  Nothing is done on devices without this
	capability.
EXPAND E - expands all characters and points by a factor E.
	EXPAND sets the expansion for all characters and points.  It is
	initially set to 1.0 and is reset to 1.0 whenever a new device is
	chosen.
FILL N [ANGLE [SEPN [PHASE]]] - Sets the fill area style to N.
	FILL sets the fill type.  The fill type is identified by N, where N
	refers to one of the following:
	    1 : solid
	    2 : hollow
	    3 : hatched
	    4 : cross-hatched
	The fill type is initially set to 1 (solid) and is reset to 1 whenever
	a new device is chosen.  If the fill type is hatched or cross-hatched,
	optional arguments can be supplied that affect the way the hatching
	will be done.  Up to three additional arguments may be provided.
	ANGLE specifies the angle the hatch lines make with the horizontal, in
	degrees, increasing counterclockwise.  SEPN is the spacing of the
	hatch lines.  The unit spacing is 1 percent of the smaller of the
	height or width of the view surface.  PHASE is an offset value and is
	a real number between 0 and 1.  The hatch lines are displaced by this
	fraction of SEPN from a fixed reference.  Adjacent regions hatched
	with the same PHASE have contiguous hatch lines.  To hatch a region
	with alternating lines of two colors, fill the area twice: once with
	PHASE=0.0 in one color and PHASE=0.5 in the other color.  The default
	value for ANGLE is 45.0 degrees, SEPN is 1.0, and PHASE is 0.0.
FIT style [N] [P1 P2 P3 ...] - Fits a curve to the (x,y) data pairs.
	FIT will solve either for a linear fit of the form:  "y = a + bx" by
	either the (a) Least Squares method ("lsqfit"); or (b) Criterion of
	Least Absolute Deviations ("medfit"); or will solve for a Gaussian fit
	of the form "y = a * exp(-((x - b)/c)**2)".  The data that comprise
	the "x" and the "y" in these equations are from the most recent call
	to the XCOLUMN and YCOLUMN commands.  For a linear fit, there is only
	one required argument, STYLE, which specifies which type of linear fit
	to perform.  The only possible values of STYLE are "lsqfit" and
	"medfit".  The fit coefficients and the corresponding errors in the
	fit are displayed at the command line.  When using the "lsqfit"
	technique, estimates of the measurement errors may be included by
	reading the error values with the ECOLUMN command.  The optional
	parameters provide a way to assign the fits and the error estimates to
	User Variables (see the SET command).  The "lsqfit" returns (in this
	order) the parameters "a" and "b" along with a chi-square for the fit
	and sigma errors on the estimates of "a" and "b".  If data in the most
	recent call to ECOLUMN was used to specify errors on the observation
	points, a "goodness of fit" is also returned.  If, however, no errors
	are specified, the correlation coefficient is returned in place of the
	"goodness of fit".  The "medfit" returns (in this order) the fit
	parameters "a" and "b" along with "absdev" (the mean absolute
	deviation in the "y" direction).  As an example, the command fit
	lsqfit \0 \1 will only assign the fit parameters "a" and "b" to the
	User Variables \0 and \1 and the remaining items will be ignored (but
	still displayed at the command line).
	For Gaussian fits, there are two required arguments:  STYLE and N,
	where STYLE must be "gaussian" and N specifies the number of Gaussians
	to fit.  The number of optional parameters that may follow is governed
	by the value of N.  Optional arguments should follow in groups of 3's
	in the following order:  amplitude, mean, and full width at half
	maximum.  Assignment of the output values follows as for linear fits.
	If the 3*N+1 parameter is present, it is set to the chi-square of the
	fit.  Setting any parameter to it's negative holds that value fixed
	during the fit.  For example:
	    set \1 1.0   # Guess at amplitude.
	    set \2 5.0   # First guess at X-position of peak.
	    set \3 -2.3  # Input FHWM and hold this fixed during fit.
	    fit gaussian 1 \1 \2 \3 \4  # Fit 1 Gaussian and store fit
	          # and chi-square in \1, \2, \3, and \4, respectively.
FONT N - Sets the font type to type N.
	FONT sets the font type to one of the available fonts.  The argument N
	selects the font used for subsequent text plotting.  The font type is
	initially set to 1 ("normal") and is reset to 1 whenever a new device
	is chosen.  Currently, four fonts are available and can be set by
	setting the parameter N to one of the following values:
	    1 : (default) a simple single-stoke font ("normal" font)
	    2 : roman font
	    3 : italic font
	    4 : script font
	The font may also be temporarily changed within a text string by using
	the escape sequences: \fn, \fr, \fi, or \fs.
FREE item1 [item2 [...]] - releases items created with the NEW command.
	FREE will remove the user specified variable(s) from WIP.  In
	addition, it releases (i.e. frees) the memory associated with each
	ITEM.  At least one ITEM is required and each ITEM listed specifies
	the name of the string variable, user variable, or vector (without any
	index) to release.
GLOBE [nlong nlat] - draws a "globe" with nlong/nlat long/lat lines.
	GLOBE draws a "globe" for use in Aitoff (Hammer) projections.  The
	"globe" that is drawn is an outline of the entire sky centered on the
	position (L, b) = (0, 0).  There are two optional parameters.  The
	first optional parameter NLONG represents the number of longitude
	lines that are drawn and the optional parameter NLAT represents the
	number of latitude lines that are drawn.  If these arguments are
	omitted, the values of NLONG = 5 and NLAT = 3 will be used for
	defaults.  Also see the command AITOFF.
HALFTONE [MIN MAX [N [BLANK]]] - produces a halftone plot of an image.
	HALFTONE draws a plot of the array read with the IMAGE command over
	the subimage region selected with the SUBIMAGE command according to
	the coordinate transformation matrix specified by the TRANSFER command
	and the current image transfer function (see the ITF command).  If the
	device permits, colors can be preassigned to the halftone values with
	any of the PALETTE, LOOKUP, RGB, or HLS commands (whenever a new
	device is selected, the palette is reset).  The first two optional
	parameters allow the user to specify the intensity range for the
	plot.  If the optional parameters MIN and MAX are not present, then
	HALFTONE will use the image minimum and maximum.  The next optional
	parameter, N, if present, indicates that histogram equalization should
	be performed using N bins.  If this parameter is present and is set to
	zero, then the full number of color table entries will be used in the
	binning.  If this is not present, no equalization will be done.  The
	last optional parameter BLANK is used to specify a blank value in the
	image to ignore when doing histogram equalization.  It defaults to
	-99.  Histogram equalization is only applied to data within the
	current subimage region and within the minimum and maximum intensity.
	NOTE: Histogram equalization changes the current LUT.  The LUT must be
	reset before calling the HALFTONE command again.
HARDCOPY - causes a stored printer plot to be plotted.
	If the current device selected is a hardcopy unit, then the HARDCOPY
	command will cause the output file to be closed and the file spooled
	to the printer.  How the file is printed is determined by the string
	variable "print" (see the command SET).  By setting "print" to the
	string "ignore", automatic printing can be disabled.  By default, the
	string variable "print" is set to "lpr" (use the command 'echo print'
	to display the current value of "print").
HEADER [XTYPE [YTYPE]] - loads header information of the current image.
	HEADER sets the transfer function and World (User) limits of the box
	region for the current image.  This function makes use of the current
	SUBIMAGE values to fix the World coordinate range.  If the optional
	arguments XTYPE and YTYPE are not present, they are set to the current
	values of the string variables "XHEADER" and "YHEADER", respectively.
	If only one argument is present, both XTYPE and YTYPE are set to this
	value.  Currently, there are 7 possible values for XTYPE and YTYPE
	used to control the resulting header arrangement:
	    rd : Right ascension/declination (absolute coordinates).
	    so : Arcsecond offset positions.
	    mo : Arcminute offset positions.
	    po : Pixel offset positions.
	    px : Absolute pixel positions.
	    gl : General linear coordinates.
	    go : General linear offset coordinates.
	All offset arguments are relative to the value of the user variables
	CRVALX and CRVALY.  The option "rd" includes a 15*cos(dec) factor
	applied to the right ascension term.  Incorrect options are treated as
	if "px" was selected.  The options "gl" and "go" apply no additional
	scaling factor to the header variables.  If the image headers CRVAL,
	CRPIX, and CDELT are not present for that axis or are all set to 0,
	the coordinate transfer function will be set to its default value (see
	the command TRANSFER) and the world limits to the image range in
	pixels.  NOTE: Currently, the conversion is fixed to be from radians
	to arcseconds (or seconds of time) for MIRIAD images; degrees to
	arcseconds for FITS images; and no conversion for BASIC images.
HELP xxx - prints an explanation of the command xxx.
	Without any argument, HELP prints a one line description of every
	command.  With the name of a command as an argument, HELP prints more
	information on that particular command.  The command 'help ?' will
	provide a list of all available command and macro names.
HI2D bias [slant [center]] - draws a histogram of the data read by IMAGE.
	HI2D plots a series of cross-sections of the current image (see
	IMAGE).  Each cross-section is plotted as a hidden line histogram.
	The one required argument, BIAS, specifies a bias value to be applied
	to each successive cross-section (in order to raise it above the
	previous one).  BIAS is in the same units as the image data.  If the
	optional parameter SLANT is present, it is an integer value offset to
	be applied to each successive cross-section (in the X-direction).  If
	SLANT is greater than 0, then the plot slants to the right; less than
	0, it slants to the left.  The default value for SLANT is 0 (no
	slant).  If the optional argument CENTER is present and equal to 1
	(the default), then the individual X values denote the center location
	of the bin; otherwise, the X values denote the lower edge (in X) of
	the bin.
HISTOGRAM [MIN MAX [N]] - draws a histogram of the data read by XCOLUMN.
	HISTOGRAM connects the coordinates read by XCOLUMN as a histogram.  If
	the optional arguments MIN and MAX are present, they are used to
	specify the minimum and maximum of the histogram.  Furthermore, an
	optional parameter N can specify the number of bins to divide up the
	histogram.  At present, N may not exceed 200.  By default, MIN and MAX
	are set to the minimum and maximum of the data read by XCOLUMN and N
	is set to 5.  The user should set the limits (see the command LIMITS)
	of the box before calling the HISTOGRAM command.
HLS K hue light sat - sets the color representation using the HLS system.
	HLS sets the color representation of the color index K to the provided
	values of Hue-Lightness-Saturation.  HUE is represented by an angle in
	degrees, with red at 120, green at 240, and blue at 0 (or 360).  LIGHT
	ranges from 0 to 1, with black at lightness of 0 and white at
	lightness 1.  SAT ranges from 0 (gray) to 1 (pure color).  HUE is
	irrelevant when SAT is 0.  If K is greater than the maximum color
	index of the device, then this call will be ignored (use the command
	'echo cmin cmax' to display the current color range).
ID - puts an identification label at the bottom of a plot.
	ID puts the name of the user and the current date and time at the
	bottom of the plot region.  If the environment variable PGPLOT_IDENT
	is defined and the current device is a hardcopy device (the command
	'echo hardcopy' will return 1 if this is true), then this call is
	automatically done when the device is finally closed (see the command
	HARDCOPY).
IF EXPRESSION XXX [...] - executes xxx if EXPRESSION is true.
	IF allows conditional execution of macros and commands.  The macro or
	command XXX is executed only if the conditional test of the expression
	is TRUE (non-zero).  The EXPRESSION may be a simple (X OP Y)
	expression where the parameters X and Y may be any numerical value or
	user variable (see the SET command) and OP is the condition to test
	and is defined TRUE for the following:
	    op : Test
	------------------------------------------------------
	    == : X equal to Y;
	    != : X not equal to Y;
	    <  : X less than Y;
	    >  : X greater than Y;
	    <= : X less than or equal to Y;
	    >= : X greater than or equal to Y;
	    && : X and Y are non-zero;
	    || : X or Y are non-zero;
	    ^  : X or Y, but not both, are non-zero.
	If the test consists of more than just a simple (X op Y) test, then
	the entire expression MUST be enclosed by parenthesis.  As an example,
	    if ((x1 < x2) && (y1 < y2)) limits x2 x1 y1 y2
	will only execute the LIMITS command if X1 is less than X2 AND Y1 is
	less than Y2.  Note also that this example illustrates that the usual
	parameters/arguments may follow the macro or command name.  See the
	command SET for a more detailed description of EXPRESSION.
IMAGE fspec [plane [badpixel [order]]] - reads in an image from file "fspec".
	IMAGE loads an array into WIP for use with plotting commands like
	CONTOUR and HALFTONE.  Currently, WIP tests the file to determine its
	file type (i.e.  FITS, MIRIAD, BASIC, etc.) and then loads it into
	available memory.  The optional parameter PLANE selects which plane of
	a data cube to load.  The default value for PLANE is 1.  IMAGE trys to
	read available header information which will be useful for setting the
	coordinate transformation matrix (see the command TRANSFER) after the
	image is read into memory (with the command HEADER).  The current
	subimage values (see the command SUBIMAGE) are reset to the full array
	size of the new image and the user variables CRVALX/Y, CRPIXX/Y, and
	CDELTX/Y may be set to the newly read header values (if they can be
	read).  The subimage values, 6 user variables, and the transformation
	matrix are used to determine where the plot will appear.  In order to
	correctly set the transformation matrix with the command HEADER, the
	values of CRVAL, CRPIX, CDELT, and CTYPE must be present for the first
	two axes.  The next optional parameter BADPIXEL may be specified
	(after PLANE) as the value for blanked or masked pixels.  By default,
	these will be set to -99.  This value may be helpful for use with the
	CONTOUR command.  The final optional parameter ORDER permits the image
	to be smoothed on reading.  The parameter ORDER may take on a value of
	0, 1, or 2 and represents the order of the fit.  A value of 0 (or if
	it is not provided) means to apply no smoothing (the default).
	NOTE: Current image types include:  basic, Miriad, and FITS.  BASIC
	image name syntax is: filename`columnsXrows[`offset] where rows and
	columns are in pixels and the optional offset is in bytes from the
	beginning of the file.  The character 'X' determines the size of each
	element and is 'b' for unsigned bytes; 's', signed 2 byte integers;
	'l', signed 4 byte integers; 'r', 4 byte floating point; 'd', 8 byte
	double precision floating point.
INITIALIZE V N EXPRESSION - Sets V to the result of EXPRESSION.
	INITIALIZE evaluates the EXPRESSION (see the command SET) and sets
	every element of the array (vector) user variable V to the result.  If
	N is less than zero, the current size of the vector variable V is
	used.  If N is zero, no expression is needed and the vector is set to
	size zero (empty).  If N is greater than zero and an expression is
	present, the first N elements of the vector are set to the result of
	the expression.  If the expression is missing, the size of the vector
	will be reset.
INPUT fspec - reads plot commands from file "fspec" and executes them.
	INPUT reads plot commands from a file and treats them exactly as if
	they were typed:  commands are executed or can be inserted or macros
	may be defined.  Unlike interactive mode, individual commands are NOT
	saved in the command buffer (see BUFFER).  NOTE: Macros are not
	redefined so care should be taken to insure that the proper macro is
	being executed.
INSERT [N [macro]] - commands are inserted before command N in a macro.
	INSERT enters insert mode (indicated by the INSERT> prompt) and
	subsequent commands are inserted, without execution, into the named
	macro until an END command is encountered.  Commands are numbered as
	shown by the command LIST.  Without any arguments, INSERT inserts
	commands at the end of the command buffer.  If N is present but no
	macro name is given, then commands are inserted before line N in the
	command macro (BUFFER).  With the MACRO argument, INSERT starts
	inserting just before line number N in macro MACRO.  NOTE: The command
	buffer macro name is BUFFER.
ITF N - sets the current image transfer function to N.
	ITF sets an internal parameter such that all subsequent image drawing
	functions (IMAGE and WEDGE) act on the transformed image.  Acceptable
	values for N and their meanings follow:
	    0 : linear
	    1 : logarithmic
	    2 : square-root
	The initial value of the image transfer function is 0 and is reset to
	0 whenever a new device is selected.
LABEL STR - writes the string STR at the current cursor position.
	LABEL writes the string STR (which starts at the current cursor
	position and continues to the last non-space character in the label
	string).  The string's size and the angle it is displayed are
	controlled by the most recent call to the commands EXPAND and ANGLE.
LCUR [NPTS] - draws a line using the cursor.
	LCUR allows a polyline to be drawn using the cursor.  Vertices may be
	added or removed by locating the cursor at a desired point and
	selecting the key 'A' (Add) or 'D' (Delete) or may terminate the
	command with the key 'X' (eXit).  The vertices are stored in the
	XCOLUMN and YCOLUMN arrays and may be redrawn by subsequent calls to
	this command.  If the optional parameter NPTS is given, it is used as
	the number of points in the previous call to this command.  To
	initialize the command, set NPTS to 0.  By default, NPTS is set to the
	current value of the number of points in the most recent call to the
	XCOLUMN and YCOLUMN commands.
LDEV - lists the devices currently available.
	LDEV lists (to standard output) the names of the installed devices
	known to the current version of WIP.
LEVELS [L1 L2 ...] - sets the contour levels for a contour plot.
	LEVELS establishes the contour values for use in a contour plot.
	Currently, the maximum number of levels available is 40.  This array
	of levels may be augmented if a call to the command SLEVEL is done
	prior to a call to the CONTOUR command.
LIMITS [X1 X2 Y1 Y2] - sets the World limits of the plot.
	LIMITS sets the World (user) coordinate system of the plot window.
	All coordinates from XCOLUMN, YCOLUMN, MOVE, DRAW, etc., are relative
	to these limits.  If no arguments are present, then the data from the
	most recent XCOLUMN and YCOLUMN commands are used to set the limits.
LINES L1 L2 - limits the X, Y, E, and PCOLUMN file read to lines L1-L2.
	LINES sets the range of lines read from the data file by the commands
	XCOLUMN, YCOLUMN, ECOLUMN, and PCOLUMN.  This is useful to avoid
	non-data lines.  The argument L1 is also used to specify the line that
	the command STRING will use to extract a string variable.
LIST [L1 [L2 [xxx]]] - lists the commands of macro xxx.
	LIST lists the commands of the named macro.  If there are no
	arguments, the macro BUFFER (the command buffer) is listed.  If one
	argument is given, then the commands from L1 to the end of the macro
	BUFFER is shown.  With two arguments, lines L1 to L2 are shown.  If
	the macro name xxx is also entered as the third argument, then that
	macro is listed over the inclusive line range of L1 to L2.  The
	numbers assigned to commands by LIST should be the ranges used by
	calls to the commands DELETE and INSERT.  NOTE: The command buffer
	macro name is BUFFER.
LOGARITHM name [scale] - takes the scaled logarithm of vectors and images.
	LOGARITHM takes the base 10 logarithm of either vectors or images.
	The argument NAME specifies either a vector name (e.g. "x") or an
	image name (currently, only the name "image" is acceptable).  If the
	value of the vector or image is greater than zero, the logarithm is
	taken and this result is multiplied by the value of SCALE.  If SCALE
	is not present, a value of 1.0 is used.  SCALE may be any valid
	numeric expression (see the command SET).  LOGARITHM uses -50 for the
	logarithm of 0 or negative numbers and does not scale these values.
LOOKUP [N] - loads a RGB color lookup table.
	LOOKUP uses the values read by the most recent call to the commands
	XCOLUMN, YCOLUMN, ECOLUMN, and PCOLUMN to load values into the color
	lookup table.  This is a more compact (and correct) method for loading
	an entire table than the single color index commands RGB and HLS.  All
	values in the XCOLUMN, YCOLUMN, ECOLUMN, and PCOLUMN data must be
	between 0 and 1.  The XCOLUMN data correspond to the red values,
	YCOLUMN to green, and ECOLUMN to blue.  The PCOLUMN data identifies
	the ramp intensity level for the corresponding RGB values.  Colors on
	the ramp are linearly interpolated from neighboring levels.  If the
	optional parameter N is present and is negative, then the resulting
	lookup table will be flipped.  By default (if the optional argument N
	is missing or is positive), the RGB table is loaded directly (not
	flipped).
LOOP count xxx [p1 p2 ...] - executes the macro xxx COUNT times.
	LOOP allows for multiple execution of a macro.  The macro xxx is
	executed COUNT times.  The optional parameters P1, P2, ...  are any
	arguments needed to be passed to the macro (see the DEFINE command).
	The arguments P1, P2, ... passed to the macro are NOT altered during
	each execution of the loop.
LSTYLE N - sets the current line style to N.
	All subsequent lines except for points and characters are drawn with
	line style N, where N refers to lines of the following form:
	    1 : solid
	    2 : dashed
	    3 : dot - dash - dot - dash
	    4 : dotted
	    5 : dash - dot - dot - dot
	If N is some number other than one of the line style values above, it
	is set to 1.  Also, the line style is set to 1 initially and is reset
	to 1 whenever a new device is selected.
LWIDTH N - sets the current line width attribute to N.
	LWIDTH sets an internal parameter such that all subsequent lines,
	text, and graph markers are drawn with lines of width N.  This number
	may range from the default of 1 to a maximum of 201.  Any other value
	is set to 1.  The actual thickness drawn is device dependent, but is
	approximately equal to 0.005 inches times the value of N.  The initial
	value of the line width is 1 and is reset to 1 whenever a new device
	is selected.
MACRO filename - Used to define macros using an external file.
	MACRO will read the commands from the file filename and define macros
	exactly as if they were typed interactively.  This allows macros saved
	from previous WIP sessions (using the WRITE command) to be read into
	WIP and defined.  Only macro definitions are allowed.
MINMAX [N] - list the maximum and minimum values of the current image.
	MINMAX list the maximum and minimum values of the image that has been
	read by the IMAGE command.  This command may be useful for setting
	contour levels, or adjusting a halftone plot.  The minimum and maximum
	of the current array are stored in the user variables IMMIN and
	IMMAX.  (The minimum and maximum may also be displayed using the
	command 'echo immin immax'.)  If the optional parameter N is present
	and set to any value greater than 0, then the minimum and maximum are
	explicitly recalculated.  This may be useful if the minimum and
	maximum has been found and then the logarithm of the image is
	computed.
MOVE X Y - sets the current World (user) position to (x,y).
	MOVE sets the current World (user) location to (x,y) without drawing
	any lines or text.  This simply provides a way to specify the current
	position of the cursor.
MTEXT side disp coord just str - writes the string STR relative to SIDE.
	MTEXT writes text at the position specified relative to a viewport
	side.  The parameter SIDE specifies which side of the viewport to
	place the string.  SIDE must be either `B', `L', `T', or `R' to
	specify the Bottom, Left, Top, or Right side of the viewport.
	Additionally, if SIDE is `LV' or `RV', then the string will be written
	perpendicular to the frame rather than parallel to it.  The parameter
	DISP specifies the displacement from the frame edge (in character
	height units).  If DISP is negative, then the string is written inside
	the viewport.  The parameter COORD is the location of the string as a
	fractional length of the specified edge of the viewport.  JUST
	specifies how to justify the string relative to COORD with JUST = 0
	meaning left justified; 0.5, centered; and 1.0, right justified.  The
	text STR is the (multiword) string to display.  As an example, "good"
	values used to place a string along the X axis, the Y axis, and the
	top of the plot box are:
	    mtext B 3.2 0.5 0.5 Xaxis label string
	    mtext L 2.2 0.5 0.5 Yaxis label string
	    mtext T 2.0 0.5 0.5 Top label string
	The first two examples above correspond to the syntax used by the
	commands XLABEL and YLABEL.
NCURSE [n] - marks a set of points using the cursor.
	NCURSE allows a set of points to be drawn using the cursor.  Points
	may be added or removed by locating the cursor at a desired point and
	selecting the key `A' (Add) or `D' (Delete) or may terminate the
	command with the key `X' (eXit).  The points are stored in the XCOLUMN
	and YCOLUMN arrays and may be redrawn by subsequent calls to this
	command.  If the optional parameter N is given, it is used as the
	number of points in the previous call to this command.  To initialize
	the command, set N to 0.  By default, N is set to the current number
	of points in the most recent call to the XCOLUMN and YCOLUMN
	commands.  On return, the cursor points are returned in increasing
	order of X (unlike the command OLIN).
NEW item [...] - creates a new string variable, user variable, or vector.
	NEW creates a new variable.  If more than one ITEM is present on the
	command line, then each will represent the name of a new variable to
	be created.  Each ITEM name must be unique and may not correspond to a
	pre-defined variable or any other defined variable.  Once these
	variables are created, they may be used just like the pre-defined
	variables:  the command SET will permit the value to be set/changed
	and the command ECHO may be used to display the current value.  Use
	the command FREE to release the memory associated with each ITEM.  If
	the ITEM is enclosed in double quotes (e.g. "ITEM"), a string variable
	is created.  If the ITEM has an optional size argument included, a
	vector is created.  Note that when defining a vector variable, the
	maximum number of elements should be enclosed in brackets and appear
	affixed to the end of the ITEM name (e.g.  array[10]).  If ITEM is not
	a vector or string variable, then ITEM represents a simple user
	variable.
OLIN [n] - marks a set of points using the cursor.
	OLIN allows a set of points to be drawn using the cursor.  Points may
	be added or removed by locating the cursor at a desired point and
	selecting the key `A' (Add) or `D' (Delete) or may terminate the
	command with the key `X' (eXit).  The points are stored in the XCOLUMN
	and YCOLUMN arrays and may be redrawn by subsequent calls to this
	command.  If the optional parameter N is given, it is used as the
	number of points in the previous call to this command.  To initialize
	the command, set N to 0.  By default, N is set to the current number
	of points in the most recent call to the XCOLUMN and YCOLUMN
	commands.  On return, the cursor points are returned in the order they
	were added (unlike the command NCURSE).
PALETTE K [LEV] - Sets the color palette to entry K.
	PALETTE sets the current image color array to a known look up table
	(LUT).  The argument K specifies which palette is loaded and legal
	values are displayed below.  If K is not associated with a legal
	palette value, a warning is issued and the palette remains unchanged.
	The value of K can be negative in which case, the absolute value of K
	is used and the sense of the LUT is reversed.  NOTE: Not all devices
	have color LUTs so this command may have no effect on them.  Whenever
	a device is changed, the palette resets to the default.
	    K   Palette set to...
	-------------------------------
	    0 : Background to Foreground (default).
	    1 : Gray scale.
	    2 : A rainbow.
	    3 : Heat scale.
	    4 : IRAF scale.
	    5 : AIPS scale.
	    6 : PGPLOT scale.
	    7 : Saoimage A scale.
	    8 : Saoimage BB scale.
	    9 : Saoimage HE scale.
	   10 : Saoimage I8 scale.
	   11 : DS scale.
	   12 : Cyclic scale.
	The optional parameter LEV may be provided to specify the number of
	levels into which to squeeze the palette.  If LEV is not present (or
	is negative), then the number of levels is not changed.  If LEV is
	present and set to 0, the number is reset to the maximum range for the
	current device.  If LEV is present and positive, the number of color
	levels is set to this value.
PANEL nx ny k - Sets the plot location to a subpanel.
	PANEL makes the current plot location panel K, where there are NX
	panels across and NY panels vertically.  The direction the panels run
	depends on the sign of K.  If K is positive, then the panels are
	counted across from the lower left and upwards (K = 1 specifies the
	first panel).  If K is negative, then the panels are counted across
	from the upper left and downwards.  PANEL retains a copy of the
	VIEWPORT coordinate system that is present when PANEL is first
	called.  To reset to those values, use the command panel 1 1 1; this
	will reset the plot location to the previous VIEWPORT area (this is
	also done automatically every time the current device is changed).  Be
	sure to also call panel 1 1 1 prior to changing the plot location with
	any other VIEWPORT command!  The separation between adjacent panels is
	controlled by the value of EXPAND as well as by the user variables
	XSUBMAR and YSUBMAR (see the SUBMARGIN command for more details on
	these variables).  If either NX or NY is negative, then the gap
	between the subpanels in that direction is removed.  The absolute
	value of NX and NY is always used to determine the number of
	subpanels.
PAPER width aspect - change the size of the view surface.
	PAPER changes the size of the view surface to a specified width
	(inches) and aspect ratio (height/width).  This command should only be
	used immediately after a call to the DEVICE command.
PCOLUMN n - reads point type data from column N of the current data file.
	PCOLUMN reads column N from the data file as the values of a symbol
	array.  The data read by PCOLUMN is used by the commands POINTS and
	BIN (as well as others) to represent additional data information.
PHARD devname [xxx args] - spool a plot to an alternative device.
	PHARD allows the commands in macro xxx (or the commands in the command
	buffer) to be spooled to an alternative device.  The one required
	argument DEVNAME is the name of the alternative device (see the
	command DEVICE).  If no other arguments are present, then the commands
	in the command buffer are played back (see the command PLAYBACK);
	otherwise, the named macro (xxx) is called (with any further arguments
	on the command line used as input arguments to the named macro).  If
	the named device is a hardcopy device, the HARDCOPY command is
	automatically executed at the end of the playback.  Finally, the
	current device is set to the device that was present when this command
	was called.
PLAYBACK [xxx args] - replay macro xxx or commands in the command buffer.
	PLAYBACK executes the macro xxx without storing the commands in the
	command buffer.  With an argument of BUFFER (or no argument), PLAYBACK
	replays all commands in the command buffer.  The optional arguments
	(args) are passed to the macro.
PLOTFIT [X1 X2 [STEP]] - draws a plot of the most recent fit.
	PLOTFIT uses the parameters from the most recent call to FIT to
	display a smooth curve.  The optional parameters X1 and X2 can be used
	to limit the X-range to be plotted.  They default to the full range of
	the window.  The other optional parameter is the STEP size of the
	plot.  It provides a means to make the plot smoother or more coarse.
	The STEP defaults to the mean of the difference between data in the
	most recent call to the XCOLUMN command.
POINTS [K] - draws points of the current style at each (x,y).
	POINTS draws points of the current style (see the command SYMBOL) and
	size (see the command EXPAND) at the coordinates read by the commands
	XCOLUMN and YCOLUMN.  The command PCOLUMN may be used to specify a
	SYMBOL corresponding to each (x,y) point plotted.  The format of the
	data read by the PCOLUMN command is the same as the argument for the
	SYMBOL command, except that an optional fractional part may be added
	to each symbol.  If the entry has a fractional part, it is treated as
	an expansion factor (fractional parts less than 0.01 gives the default
	expansion).  For example, an entry of 93.5 in a point column is the
	same as symbol 93, expand 0.5.  If the optional argument K is present,
	the command ECOLUMN may be used to specify a color corresponding to
	each (x,y) point plotted.  Each item of data read by ECOLUMN
	corresponds to a color index.
POLY - draws a polygon.
	POLY will draw a closed polygon based on the data from the most recent
	call to the XCOLUMN and YCOLUMN commands.  POLY will draw the polygon
	according to the graphical characteristics such as FILL and COLOR.
	Also see the command RECT.
PUTLABEL just str - writes justified text STR at the current location.
	PUTLABEL writes a string at the current cursor location with rotation
	and size specified by the ANGLE and EXPAND commands (exactly like
	LABEL).  The label is justified with respect to the current location
	according to the argument JUST: 0 for left justified; 0.5 for centered
	justified; and 1 for right justified.  If JUST is negative, the cursor
	is activated and the position of the cursor when any key is struck is
	used as the current location and the absolute value of JUST is used to
	determine the string justification.  NOTE: Because -0 will be
	interpreted as +0 by the string parser, use something like -0.001 for
	left justification when using the cursor to locate the position.
QUARTER [N] - allows quick selection of a subsection of the current image.
	QUARTER is a short cut to selecting a quadrant of the current image.
	Rather than determining pixel ranges and then calling SUBIMAGE,
	QUARTER allows the user to quickly set the corresponding pixel range.
	If the optional parameter N is present and set to 1, QUARTER selects
	the lower left quadrant; set to 2, the lower right; 3, the upper left;
	and 4, the upper right.  QUARTER, with any other value for N or if no
	argument is present, selects the inner quarter of the current image.
RANGE [X1 X2 Y1 Y2] - limits the range over which to fit.
	RANGE permits a way to limit the data used by the FIT command.  By
	default, the FIT command uses all the data read by the most recent
	call to the XCOLUMN and YCOLUMN commands.  Specifying the limits in
	one direction restricts which data will be used by the FIT command.
	If the limits in either direction are equal, then the fit is unbounded
	in that direction.
READ fspec - reads plot commands from file "fspec".
	READ reads plot commands from a file and places them in the command
	buffer.  Commands are not executed and macros are ignored.  To execute
	the commands, see the command PLAYBACK; to define macros, see the
	commands DEFINE and MACRO.
RECT xmin xmax ymin ymax - draw a rectangle, using fill-area attributes.
	RECT is like the command POLY but draws a rectangle bordered by the
	World (user) coordinate vertices (XMIN, YMIN) and (XMAX, YMAX).  RECT
	uses the current fill, line style, and line color characteristics.
RESET - full reset of the graphics state of the current plotting device.
	RESET executes a full reset of graphics state of the current plotting
	device.  The coordinate transformation matrix is reset to the default
	value (see the command TRANSFER); the current angle is set to 0 (see
	the command ANGLE); the tick mark interval and the number of minor
	tick marks is reset to 0 (see the command TICKSIZE); the image
	transfer function is reset to linear (see the command ITF); the text
	background color index is set to transparent (see the command BGCI);
	and the color, expand, fill, font, line style, and line width are all
	set to 1 (see the commands COLOR, EXPAND, FILL, FONT, LSTYLE, and
	LWIDTH).  Finally, the Palette (see the command PALETTE) is reset to
	the default palette and the number of halftone levels is reset to the
	maximum range possible for the current device.
RGB K red [green blue] - sets the color representation using the RGB system.
	RGB sets the color representation of color index K to the
	Red-Green-Blue values.  The range of values for the color value inputs
	are [0 - 1], inclusive.  If only the first two arguments are present,
	the RED value is also used to set the GREEN and BLUE values (useful
	when creating just a gray scale).  If K is larger than the maximum
	color index of the device (use the command 'echo cmin cmax' to display
	the color index range), then this call is ignored.
SCALE X [Y [K]] - sets the viewport size scale.
	SCALE allows the viewport (device) size scale to be set based on the
	range of the World (user) coordinate range.  The viewport is changed
	to the World range divided by the input scale factor (i.e. X and Y are
	in World units h per desired unit).  The optional parameter K
	specifies the desired conversion the two scale parameters will be
	performing and scales as shown below:
	    K   X and Y are dimensioned as...
	---------------------------------------------------------------
	    0 : World (user) units per normalized device coordinate.
	    1 : World units per inch.
	    2 : World units per mm.
	    3 : World units per pixel.
	If K is not present on the command line, then it is set to 2.  The
	value of Y may be omitted, in which case it is set to the same value
	as X.  However, if a value other than K = 2 is desired, both X and Y
	MUST be present.  If K is not one of the above accepted values, no
	conversion is performed.  Also, if either X or Y are less than or
	equal to 0, no conversion is performed.  As an example, if the limits
	of the current plot are 0 - 10 in the x-direction and 0 - 12 in the
	y-direction, scale 2 3 1 will produce a viewport region 5x4 inches in
	size.  Hence, it is possible to produce a viewport larger than the
	view size.
SET V EXPRESSION - sets the user variable V to result of EXPRESSION.
	SET sets the symbolic variable V to the result from evaluating the
	statement EXPRESSION.  V is a string variable if it is enclosed in
	double quotes.  If V is a string variable, then EXPRESSION represents
	the value to assign to the variable (Example: 'set "print" lpr
	-Pps').  For user and vector variables, EXPRESSION may be a simple
	syntax statement that will be evaluated.  Precedence in the expression
	is ALWAYS left to right with the inner most set of parenthesis
	evaluated first.  Hence (5 * 3 + 2) != (2 + 3 * 5) but ((5 * 3) + 2)
	does equal (2 + (3 * 5)).  Currently, a maximum of 20 nested levels of
	parenthesis is permitted.  Also note that a set of parenthesis is
	understood to mean "()", "[]", or "{}".  At the most basic level,
	EXPRESSION may just be an item that is either a number, a pre-defined
	user variable, or a vector element.  More complex EXPRESSION's may be
	generated using the operators and functions listed below.  If an item
	begins with '-', it is treated as a unary minus sign.  The current
	defined operations that act on two variables are:
	   +          add |  /         divide | max               maximum
	   -     subtract |  %  modulo divide | min               minimum
	   *     multiply |  \ integer divide |  **        exponentiation
	  ==     equal to |  >   greater than |  >= greater than or equal
	  != not equal to |  <      less than |  <=    less than or equal
	  ||   logical OR | &&    logical AND |   ^           logical XOR
	Note that min and max are used as (a min b) and (a max b).  Also, note
	that logical operations return 1 if true; 0 if false.  Current
	pre-defined functions (i.e. f(x)) are:
	  sqrt(x)          square root |    abs(x)        absolute value
	   int(x)   integer truncation |   nint(x)           nearest int
	    ln(x)    natural logarithm |    log(x)     base-10 logarithm
	   exp(x) base-e antilogarithm |  log10(x)     base-10 logarithm
	   sin(x)      sine in radians |   sind(x)       sine in degrees
	  asin(x)   arcsine in radians |  asind(x)    arcsine in degrees
	The four types of sin functions apply just as well for the four
	functions of cos and tan.  Note that either log(x) or log10(x) may be
	used for the log base 10.  Many of the symbolic and user variables are
	displayed using the SHOW command, where symbolic names are displayed
	in CAPS.  All other variables can be displayed using the ECHO
	command.  All of the user variable and vectors can then be used as
	arguments to any other command.  NOTE: The macro arguments ($1, $2,
	...) may be redefined using this command but only if the macro
	argument is a numeric user variable.
SHOW [what] - shows current limits and attributes.
	SHOW lists the values of some the symbolic and user variables,
	including the current location and plot region limits in World (user)
	and Viewport (device) coordinates, the value of the expansion and
	angle variables, the line style and width, etc.  If no arguments are
	present, then everything below is displayed.  If the optional argument
	is present, then it represents a string used to define what will be
	shown.  The options that are currently available are:
	    B : Box attributes.
	    C : Coordinate system information.
	    D : Device, Printer, and Data file information.
	    G : Graphical attributes.
	    I : Image characteristics.
	    R : Register variables (\0 - \20).
	More than one option may be selected (e.g. 'show bci') and unknown
	options are ignored.  The command ECHO may also be used to display
	user variable values.
SLEVEL type [value] - sets the type and value used to scale contour levels.
	SLEVEL is used to change the TYPE and VALUE used to scale the contour
	level array.  Initially, TYPE (the user string variable "LEVTYPE") is
	set to A and VALUE (the user variable SLEVEL) is set to 1.0 so that no
	scaling is performed.  TYPE may only be either A or P (all other
	values are treated as A) and defines the type of contour scale
	factor.  If TYPE is P, then scaling is done by percentage; A for
	absolute scaling.  VALUE represents how much the array will be
	scaled.  For example, slevel P 1 will multiply each contour level by
	1% of the image peak value.  Likewise, slevel A 1E-4 would multiply
	each contour level by 0.0001.  If the parameter VALUE is not given,
	SLEVEL will not change.  The contour level array affected is defined
	with the commands LEVELS or AUTOLEVS and is altered internally every
	time the command CONTOUR is called.
STRING name [W1 [W2]] - sets a string variable "name" from a file.
	STRING allows certain string variables to be redefined using data in
	an external file.  STRING reads one line (see the commands DATA and
	LINES) and assigns the string starting with word W1 and ending with W2
	to the string variable NAME.  If W1 is omitted or set to 0, the entire
	line is assigned.  If W1 is greater than 0, it represents the starting
	word of the assignment.  If W2 is not present, it is set to the value
	of W1.  If W2 is set to 0, it corresponds to the end of the line; if
	it less than zero, the absolute value represents the number of words
	to read; if it is greater than zero, it specifies the last word to
	read.
	Currently, the pre-defined string variables are: XBOX and YBOX (which
	are the default X and Y arguments for a call to the command BOX and
	are initially set to "BCNST" and "BCNSTV", respectively); PRINT (which
	is the default print command to spool a plot when the command HARDCOPY
	or PHARD is used); and HELPFILE (which is the full name of the help
	file).  Other pre-defined string names include XHEADER and YHEADER
	(see the command HEADER) and LEVTYPE (see the command SLEVEL).  New
	string variables may be defined using the NEW command, released with
	the command FREE, and may also be assigned to using the SET command.
SUBIMAGE xmin xmax ymin ymax - sets the index range of a subimage.
	SUBIMAGE allows the user to specify the indices of a subimage read by
	the IMAGE command.  When IMAGE reads in a new image, the minimum
	values are set to 1 and the maximum values are set to the number of
	pixels in the X and Y directions (user variables NX and NY).  Use this
	command to select a subportion of the image by entering the starting
	and ending pixels of interest.  Using the command HEADER after the
	command SUBIMAGE will reset the limits of the plot region (World
	coordinates) to the entire subimage region selected.
SUBMARGIN xmarg [ymarg] - sets the gap between individual panels.
	SUBMARGIN may be used to fix the gap size between individual frames
	when using the command PANEL.  The gap between individual panels is
	controlled by the user variables XSUBMAR and YSUBMAR (which are
	initially set to 2 in character height units).  This command is a
	convenience function to facilitate setting these variables.  The
	arguments XMARG and YMARG are used to set each of the two user
	variables.  If this command is called with only one argument, it is
	used to set both XSUBMAR and YSUBMAR.
SYMBOL N - sets the current point symbol to N.
	SYMBOL causes points to be drawn as the symbol N, where N refers to
	the graph marker or a Hershey symbol number.  The symbol number
	corresponds to the type of symbol drawn.  If the symbol number is -1,
	it draws a dot of the smallest possible size.  If the symbol number is
	between 0 and 31, it corresponds to a set of pre-defined symbols;
	between 33 and 127, it corresponds to the ASCII character in the
	currently selected font; and larger than 127, corresponds to the
	Hershey symbol of the same number.
TICKSIZE XTICK NXSUB YTICK NYSUB - sets tick intervals for the BOX command.
	TICKSIZE determines tick intervals for the command BOX.  The argument
	NXSUB refers to the number of intervals between major tick marks on
	the X-axis and XTICK refers to the interval between large ticks in
	World (user) coordinates.  If XTICK or NXSUB are 0, the box routine
	will supply it's own intervals according to the World coordinate
	limits (at least 3 major tick marks).  Likewise for NYSUB and YTICK,
	except for the Y-axis.  Setting NXSUB or NYSUB to 1 will inhibit any
	minor tick marks regardless of the arguments to the BOX command.
TRANSFER T1 T2 T3 T4 T5 T6 - specifies the image coordinate transformation.
	TRANSFER specifies the coordinate transformation between indices I and
	J of the image array and World (user) coordinates.  All two
	dimensional plot commands (for example, CONTOUR or HALFTONE) require a
	coordinate transformation function to place the image on the plot
	surface.  The World coordinates (X, Y) of the array point (I, J) are
	related by:
	    X = T1 + (T2 * I) + (T3 * J)
	    Y = T4 + (T5 * I) + (T6 * J)
	Usually T3 and T5 are zero unless the coordinate transformation
	involves a rotation or sheer.  The default transformation is (0, 1, 0,
	0, 0, 1).  Calling TRANSFER with no arguments resets the array to
	these default values.  Usually, the command HEADER is used to set the
	transformation matrix.
VECTOR [ANGLE [VENT]] - Draws a vector field as a sequence of arrows.
	VECTOR draws a vector field as a number of arrows.  The tails of the
	arrows lie at points (x,y) read by XCOLUMN and YCOLUMN, the lengths of
	the arrows "r" are read by PCOLUMN and the direction of the arrow
	(counter-clockwise from +X in degrees) is read with ECOLUMN.  See the
	command ARROW for a description of the optional parameters ANGLE and
	VENT.  NOTE: The use of PCOLUMN in this context requires SYMBOL to be
	re-executed before plotting points.
VIEWPORT VX1 VX2 VY1 VY2 - sets the physical location of the plot.
	The plot region is a rectangle within the coordinates allowed by the
	plotting device (for example, the Viewport is the region where the
	command BOX will draw its grid).  Vectors and points are truncated at
	the edge of this plot region.  VIEWPORT specifies (in normalized
	device coordinates) where the plot region is located.  Viewport
	arguments for this command range from 0 to 1, inclusive, in each
	direction for all devices.  Note that the command VSTAND is called to
	reset the Viewport coordinates every time a new device is opened.
VSIZE VX1 VX2 VY1 VY2 - sets the physical location of the plot in inches.
	VSIZE specifies (in inches) where the plot region is located.  See
	also the VIEWPORT command.
VSTAND - sets the standard (default) viewport.
	VSTAND defines the standard viewport scale.  Currently, this is a box
	with margins on each side of about 4 character heights.  This command
	is executed every time a new device is chosen.  See also the VIEWPORT
	and VSIZE commands.
WEDGE SIDE DISP THICK [MIN MAX BOXARG] - draws a halftone wedge.
	WEDGE illustrates the range of values drawn by the halftone command.
	The SIDE argument is used to specify the size and orientation of the
	wedge.  The parameter SIDE must be either `B', `L', `T', or `R' to
	specify the Bottom, Left, Top, or Right side of the viewport.  The
	DISP argument specifies the displacement from the frame edge (in
	character height units).  If DISP is negative, then the wedge is drawn
	inside the viewport.  The parameter THICK is the thickness of the
	wedge (in character height units).  The optional arguments MIN and MAX
	allow the user to specify the intensity range of the wedge.  By
	default, MIN and MAX are the values used by the most recent call to
	the HALFTONE command.  Providing the values of MIN and MAX will cause
	WEDGE to display a different range of intensities when labeling the
	wedge box.  The optional argument BOXARG permits the user to control
	how the box around the wedge is drawn (or omit it altogether).  By
	default, a simple box is drawn setting BOXARG to BCSTN/M (depending on
	the orientation); to eliminate the box, set BOXARG to 0 (for more
	information on permitted box arguments, see the BOX command).  The
	arguments from the most recent call to the TICKSIZE command are used
	to draw a box around the wedge and numerically label it.  To use the
	optional BOXARG argument, the MIN and MAX arguments must be provided.
WINADJ [xmin xmax ymin ymax] - sets limits and viewport to same aspect ratio.
	WINADJ changes the World (user) limits and adjusts the viewport so
	that the World coordinate scales are equal in x and y.  If the four
	optional parameters are present, they are used as the new World
	coordinate values; otherwise, the minimum and maximum values of the
	XCOLUMN and YCOLUMN arrays are used.  Typical usage is (after an image
	is loaded) to rescale the viewport so that the image has the proper
	aspect ratio.  For example, using the command 'winadj 0 nx 0 ny' after
	the IMAGE command BUT before the HEADER command will produce square
	pixels.
WRITE fspec xxx - writes macro xxx to file "fspec".
	WRITE the commands making up a macro to a file.  If the macro name XXX
	given is all, all macros currently defined and the entire command
	buffer (BUFFER) are written to the file.  If the macro name XXX is
	macros, then only the currently defined macros are written to the file
	(i.e. the command buffer BUFFER is not written).  Otherwise, XXX
	represents a list of macro names to be written in the output file.
	NOTE: This command will OVERWRITE any currently existing file.
XCOLUMN N - reads X data from column N of the current file.
	XCOLUMN reads column N from the data file as the values of the X
	coordinates of the data points.
XLABEL str - writes the label STR centered under the X axis.
	XLABEL writes a string centered under the X axis drawn by the command
	BOX.  Also see the command MTEXT.
YCOLUMN N - reads Y data from column N of the current file.
	YCOLUMN reads column N from the data file as the values of the Y
	coordinates of the data points.
YLABEL str - writes the label STR centered left of the Y axis.
	YLABEL writes a string centered left of the Y axis drawn by the
	command BOX.  Also see the command MTEXT; especially if the
	displacement of the text is insufficient to avoid the axis numbers.