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<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 3//EN">
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		<TITLE>User's Reference - AutoGlyph</TITLE>
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		<H3><A name="HDRAUTOGLY" ></A>AutoGlyph</H3>
		<A NAME="IDX381"></A><A NAME="IDX382"></A>
<P><STRONG>Category</STRONG>
<P>
<A HREF="refgu008.htm#HDRCATANN">Annotation</A>
<A NAME="IDX383"></A>
<A NAME="IDX384"></A>
<P><STRONG>Function</STRONG>
<P>
Assigns an appropriate glyph to each point in a data field.
<P><STRONG>Syntax</STRONG>
<PRE><STRONG>
glyphs</STRONG> = AutoGlyph(<STRONG>data, type, shape, scale, ratio, min, max</STRONG>);
</PRE>
<P><STRONG>Inputs</STRONG>
<BR>
<TABLE BORDER>
<TR>
<TH ALIGN="LEFT" VALIGN="TOP" WIDTH="20%">Name
</TH><TH ALIGN="LEFT" VALIGN="TOP" WIDTH="20%">Type
</TH><TH ALIGN="LEFT" VALIGN="TOP" WIDTH="20%">Default
</TH><TH ALIGN="LEFT" VALIGN="TOP" WIDTH="40%">Description
</TH></TR><TR>
<TD ALIGN="LEFT" VALIGN="TOP" WIDTH="20%"><TT><STRONG>data</STRONG></TT>
</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="20%">data field
</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="20%">none
</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="40%">set of points to which glyphs
will be assigned
</TD></TR><TR>
<TD ALIGN="LEFT" VALIGN="TOP" WIDTH="20%"><TT><STRONG>type</STRONG></TT>
</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="20%">scalar, string, field, or group
</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="20%">input dependent
</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="40%">glyph type
</TD></TR><TR>
<TD ALIGN="LEFT" VALIGN="TOP" WIDTH="20%"><TT><STRONG>shape</STRONG></TT>
</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="20%">scalar
</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="20%">1.0
</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="40%">factor to describe shape of glyph
(must be greater than 0)
</TD></TR><TR>
<TD ALIGN="LEFT" VALIGN="TOP" WIDTH="20%"><TT><STRONG>scale</STRONG></TT>
</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="20%">scalar
</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="20%">1.0
</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="40%">scale factor for size of glyphs
(must be greater than 0)
</TD></TR><TR>
<TD ALIGN="LEFT" VALIGN="TOP" WIDTH="20%"><TT><STRONG>ratio</STRONG></TT>
</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="20%">scalar
</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="20%">0.05 or 0
</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="40%">ratio in size (scalars or
vectors) between smallest and largest
glyphs (must be greater than or equal to 0)
</TD></TR><TR>
<TD ALIGN="LEFT" VALIGN="TOP" WIDTH="20%"><TT><STRONG>min</STRONG></TT>
</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="20%">scalar or field
</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="20%">min of data value or 0
</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="40%">data value that gets minimum-size
glyph
</TD></TR><TR>
<TD ALIGN="LEFT" VALIGN="TOP" WIDTH="20%"><TT><STRONG>max</STRONG></TT>
</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="20%">scalar or field
</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="20%">max of data
</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="40%">data value that gets maximum-size
glyph
</TD></TR></TABLE>
<P><STRONG>Outputs</STRONG>
<BR>
<TABLE BORDER>
<TR>
<TH ALIGN="LEFT" VALIGN="TOP" WIDTH="25%">Name
</TH><TH ALIGN="LEFT" VALIGN="TOP" WIDTH="25%">Type
</TH><TH ALIGN="LEFT" VALIGN="TOP" WIDTH="50%">Description
</TH></TR><TR>
<TD ALIGN="LEFT" VALIGN="TOP" WIDTH="25%"><TT><STRONG>glyphs</STRONG></TT>
</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="25%">color field
</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="50%">set of glyphs
</TD></TR></TABLE>
<P><STRONG>Functional Details</STRONG>
<P>
This module creates a glyph, or representation (e.g., an arrow), for
each data value in a data field  <TT><STRONG>data</STRONG></TT>.
For data dependent on positions, a glyph is placed at the corresponding
position.
For data dependent on connections, a glyph is placed at the center of
the corresponding connection element.
If there is no "data" component, a glyph is placed at each
position.
<P>
The "base" size

(i.e. size of a glyph for the average data value)

is based on AutoGlyph&#39;s estimate of an appropriate glyph
size, as modified by <TT><STRONG>scale</STRONG></TT>.
<P>
For "text" glyphs, a "data" component is required.
<P>
AutoGlyph differs from the Glyph module in the interpretation of the
<TT><STRONG>scale</STRONG></TT> parameter.
For AutoGlyph, you specify the size of the glyphs relative to
the default-size glyph chosen by AutoGlyph.
In contrast, when using Glyph, you may specify a scaling factor that is
multiplied by the data value to obtain the size of the glyph in
world units.
<TABLE CELLPADDING="3">
<TR VALIGN="TOP"><TD><P><B><TT><STRONG>data</STRONG></TT>
</B></TD><TD><P>is the data field for which glyphs are to be created.
</TD></TR><TR VALIGN="TOP"><TD><P><B><TT><STRONG>type</STRONG></TT>
</B></TD><TD><P>specifies the kind of glyph to be used.
<P>
By default, scalar fields are represented by filled circles or spheres,
vector fields by arrows, tensor fields by groups of arrows, and
string data by text.
For 2-dimensional scalar fields, the glyphs are circles, and for
2-dimensional vector fields, the arrows are flat.
For 3-dimensional fields, spheres or rounded arrows (rockets)
are used.
<P>
The <TT><STRONG>type</STRONG></TT> parameter will override a default glyph.
If <TT><STRONG>type</STRONG></TT> is a string, it must specify one
of the following:
"arrow,"
"arrow2D,"
"circle,"
"colored text,"

"cube,"

"diamond,"
"needle,"
"needle2D,"
"rocket,"
"rocket2D,"
"sphere,"
"speedy,"
"spiffy,"

"square,"

"standard,"
or
"text."
The value "standard" specifies the default glyph type and is a
medium-quality glyph appropriate to the data; "spiffy,"
a higher-quality glyph; and "speedy," a lower-quality,
but more quickly rendered glyph.

Lower quality glyphs also consume less memory.

<P>
You may alternatively specify <TT><STRONG>type</STRONG></TT> as a scalar
value between 0 and 1, where&#58;
<UL COMPACT>
<LI>0 is the same as "speedy"
<LI>1 is the same as "spiffy"
<LI>0.5 is the same as "standard"
</UL>
There are approximately 5 different quality glyphs for each glyph type.
The one closest to the value specified is used.
<P>
Specifying "text" or "colored text" for
<TT><STRONG>type</STRONG></TT> puts a text representation of the data value
at each point.
For text glyphs, the text is by default 15 pixels high, and the
<TT><STRONG>shape</STRONG></TT>, <TT><STRONG>ratio</STRONG></TT>,
<TT><STRONG>min</STRONG></TT>, and
<TT><STRONG>max</STRONG></TT>
parameters have no effect.
The <TT><STRONG>scale</STRONG></TT> parameter can be used to increase or
decrease the size of the text glyphs.
For example, specifying <TT><STRONG>scale</STRONG></TT> = 2 makes the text 30
pixels high.
The difference between "text" and "colored text" is that text
is always white when "text" is specified, but will be the color
of the input if "colored text" is specified.
Note that after the AutoGlyph module, Color can be used to color text
glyphs to a different color if desired.
The font for the text glyphs can be specified by appending
"font = <I>fontname</I>" to "text" or
"colored text," where <I>fontname</I> is
any of the defined fonts supplied with Data Explorer:
<PRE>
area          gothicit_t       pitman                roman_ext
cyril_d       greek_d          roman_d               script_d
fixed         greek_s          roman_dser            script_s
gothiceng_t   italic_d         roman_s               variable
gothicger_t   italic_t         roman_tser
</PRE>
For more information,
see <A HREF="usrgu076.htm#HDRAPC">Appendix E. "Data Explorer Fonts"</A> in
<I>IBM Visualization Data Explorer User&#39;s Guide</I>.
In addition, you may supply user-defined fields and groups to the
<TT><STRONG>type</STRONG></TT> parameter (see
<A HREF="#SPTTYPE">reference #1</A>).
</TD></TR></TABLE>
<P>
The remaining five parameters are interpreted somewhat differently,
depending on whether the type of data involved are (1) scalar
or (2) vector or tensor.
<P>
<H4><A NAME="Header_37">Scalar Data</A></H4>
<TABLE CELLPADDING="3">
<TR VALIGN="TOP"><TD><P><TT><STRONG>shape</STRONG></TT>
</TD><TD><P>is ignored for scalar data
</TD></TR><TR VALIGN="TOP"><TD><P><TT><STRONG>scale</STRONG></TT>
</TD><TD><P>sets the scale factor for the size of the glyphs relative to the
default glyph.
</TD></TR><TR VALIGN="TOP"><TD><P><TT><STRONG>ratio</STRONG></TT>
</TD><TD><P>controls the ratio between the smallest and the largest glyphs.
The default value is 0.05.
</TD></TR><TR VALIGN="TOP"><TD><P><TT><STRONG>min</STRONG></TT> and
<TT><STRONG>max</STRONG></TT>
</TD><TD><P>are the data values used to set glyph sizes.
Their default values are the minimum and maximum data values
respectively.
Unless you change <TT><STRONG>ratio</STRONG></TT> from its default value of
0.05, the glyphs representing data with a value of
<TT><STRONG>min</STRONG></TT> are 5 percent the size
of the glyphs representing data with a value
of <TT><STRONG>max</STRONG></TT>.
You can make the size of the glyphs directly proportional to the data
value by setting both <TT><STRONG>min</STRONG></TT> and
<TT><STRONG>ratio</STRONG></TT> to 0.
<P>
Data values smaller than <TT><STRONG>min</STRONG></TT> are colored pale pink,
unless the original positions already had colors, in which
case the colors are left unchanged.
These data values are represented by glyphs of a size proportional to
<BR>
<TT><STRONG>min</STRONG></TT> &#45; <I>datavalue</I>.
</TD></TR></TABLE>
<P>
<H4><A NAME="Header_38">Vector and Tensor Data</A></H4>
<TABLE CELLPADDING="3">
<TR VALIGN="TOP"><TD><P><B><TT><STRONG>shape</STRONG></TT>
</B></TD><TD><P>is used to change the thickness of the glyph relative to
its length.
The default value for <TT><STRONG>shape</STRONG></TT> is 1 (e.g., to make a
glyph twice as thick, set this parameter to twice the default
value (i.e., to 2).
</TD></TR><TR VALIGN="TOP"><TD><P><B><TT><STRONG>scale</STRONG></TT>
</B></TD><TD><P>sets the scale factor for the size of the glyphs relative to the
default glyph.
</TD></TR><TR VALIGN="TOP"><TD><P><B><TT><STRONG>ratio</STRONG></TT>
</B></TD><TD><P>determines which data values are displayed.
To display only those values larger than
0.5 * <TT><STRONG>max</STRONG></TT>,
set this parameter to 0.5.
The default value is 0.0.
</TD></TR><TR VALIGN="TOP"><TD><P><B><TT><STRONG>min</STRONG></TT> and
<TT><STRONG>max</STRONG></TT>
</B></TD><TD><P>are the data values used to set glyph sizes.
<P>
For <I>

3x3 symmetric

tensor data</I>
three arrows are drawn, representing the
eigenvectors of the matrix.

For <I> 2x2 symmetric tensor data</I>
two arrows are drawn, representing the
eigenvectors of the matrix.

For <I>vector data</I>, one arrow is drawn, representing the
magnitude of the data.
The default value of <TT><STRONG>min</STRONG></TT> is 0 (zero), and the
length of the glyphs is always directly proportional to the
magnitude of the data
(or the magnitude of the eigenvector).
If you set <TT><STRONG>min</STRONG></TT> to a value greater than zero, all
data with a magnitude smaller than <TT><STRONG>min</STRONG></TT> are
represented by a dot if <TT><STRONG>type</STRONG></TT> is
"needle," and by a small sphere otherwise.
This can be useful to weed out small and perhaps noisy vectors.
You can also set <TT><STRONG>ratio</STRONG></TT> to a value larger than zero;
in that case, all data with a magnitude smaller than
<TT><STRONG>ratio</STRONG></TT> &times;
<TT><STRONG>max</STRONG></TT> is shown
by a small sphere or dot.
This allows you, for example, to set <TT><STRONG>ratio</STRONG></TT> = 0.5
to see only those vectors with a magnitude greater than half of
<TT><STRONG>max</STRONG></TT>.
<P>
If you have vector data and want to show all the vectors as having the
same length, you can use the <TT><STRONG>norm</STRONG></TT> function in
the Compute module to normalize all the vectors to unit
magnitude before passing them to AutoGlyph.
</TD></TR></TABLE>
<P>
You can also use a field as the input for <TT><STRONG>min</STRONG></TT> and
<TT><STRONG>max</STRONG></TT>, in which case the statistics of that
field are used instead.
If the input <TT><STRONG>data</STRONG></TT> is changing from frame to frame,
and you want to keep the glyph sizes consistent from frame to frame,
you can use the entire field or series as the input for
<TT><STRONG>min</STRONG></TT> and <TT><STRONG>max</STRONG></TT>.
<P>
Note that if you set <TT><STRONG>min</STRONG></TT> and
<TT><STRONG>max</STRONG></TT>, and there are data
values far outside that range, then it is
possible to get very large glyphs.
This is because <TT><STRONG>max</STRONG></TT> is used to set the size scaling
for the glyphs.
Data values much larger in absolute value than <TT><STRONG>max</STRONG></TT>
have proportionally larger-sized glyphs.
<P>
<H4><A NAME="Header_39">User-supplied and Annotation Glyphs</A></H4>
<P>
You may also pass your own glyph in as <TT><STRONG>type</STRONG></TT> as the
object to place at each data point.
The dimensionality of the positions of the glyph must be either 2-D or
3-D, and the connections type must be "triangles" or
"lines."
This glyph can be any Data Explorer field (e.g., an imported object, an
isosurface, or a constructed object).
<A NAME="SPTTYPE"><I>(Ref #1.)</I></A>
<P>
There are two ways to use your own glyphs: as user-supplied glyphs and
as annotation glyphs.
<P>
<I>User-supplied Glyphs</I>
<P>
If you pass in a single field as <TT><STRONG>type</STRONG></TT>, that object
is used as a glyph.
It is drawn large or small depending on the data value, and it inherits
the color of the data point, if present.
The size of the object should be approximately unity for the default
sizing of AutoGlyph to work well.  Glyphs for scalar fields should
be centered at the origin; glyphs for vector fields should have
their base at the origin and the end that you want to point
in the direction of the vector field at (0, 1, 0);
that is, the glyph will be stretched along its
y-dimension.
You can use any combination of Scale, Rotate, and Translate to scale,
orient, and position your template glyph before passing it to
AutoGlyph.
<P>
<I>Annotation Glyphs</I>
<P>
If you pass in a group of objects as <TT><STRONG>type</STRONG></TT>,
AutoGlyph interprets these as "annotation glyphs."
Each object in the group must be a single field.
It is assumed that you want data values equal to zero to be represented
by the zero<SUP>th</SUP> glyph in the group, data values equal to
one to be represented by the first glyph in the group,
and so on.
<P>
Thus the data component of <TT><STRONG>data</STRONG></TT> in this case must
be of the type integer, unsigned integer, byte, unsigned byte,
short, or unsigned short.
The size of the glyph in the resulting output will be the size of the
glyph in the glyph group, modified by the scaling factor
<TT><STRONG>scale</STRONG></TT>.
Colors and other components will be maintained from the <I>input
glyphs</I> to the output object, rather than from the colors
of <TT><STRONG>data</STRONG></TT>.
The
<TT><STRONG>shape</STRONG></TT>,
<TT><STRONG>ratio</STRONG></TT>,
<TT><STRONG>min</STRONG></TT>,
and
<TT><STRONG>max</STRONG></TT>
parameters are ignored for annotation glyphs.
Annotation glyphs should be positioned at the origin.
You can use any combination of Scale, Rotate, and Translate to scale,
orient, and position your template glyph before passing it
to AutoGlyph.
<P><STRONG>Components</STRONG>
<P>
Creates new "positions" and "connections" components.
In the case of a 3-D glyph, a "normals" component is added for
shading purposes.
All components that match the dependency of the "data" component
are propagated to the output;
all others are not.
If the input has "binormals" and "tangent" components, they
are not propagated to the output.
<P><STRONG>Example Visual Programs</STRONG>
<PRE>
AnnotationGlyphs.net              ThunderGlyphSheet.net
ConnectingScatteredPoints.net     UsingGlyphs.net
PickStreamline.net                UsingTextAndTextGlyphs.net
ProbeText.net                     SIMPLE/AutoGlyph.net
</PRE>
<P><STRONG>See Also</STRONG>
<P>
&nbsp;<A HREF="refgu068.htm#HDRGLYPH">Glyph</A>,
&nbsp;<A HREF="refgu126.htm#HDRSAMPLE">Sample</A>
<TABLE BORDER WIDTH="100%"><TR><TH ALIGN="LEFT">How to Avoid Stretching or
Squashing Glyphs</TH><TR><TD>
<A NAME="SPTAVOID"></A>
<P>
Users often use the Scale module to scale a collection of objects
prior to rendering, if the axes have very different scales.
This can cause a problem if the visualization includes glyphs, as the
glyphs will be stretched or squashed as well.
You can place the Scale module before Glyph or AutoGlyph, but if you
want AutoAxes to show the original (rather than the scaled)
position values, this will not work.
One way of solving this problem lies in the fact that Glyph and
AutoGlyph can accept a user-defined Glyph:
<P>
Give either module a "user-defined" glyph that is
<I>inversely</I> squashed, so that when you use
Scale, the glyph ends up with the correct shape.
Proceed as follows:
<UL COMPACT>
<LI>
Create a field with a single point at the origin, using Construct
(&#91;0 0 0&#93;, data = 0) for scalar (sphere) glyphs
<LI>Feed this field to either module to make a single sphere
or arrow.
<LI>Now scale the glyph, using a scale factor that is the inverse of
the one you want to use on the entire data set.
For example, if you are going to scale your data by
&#91;1 1 .001&#93;, then scale the single glyph
by &#91;.001 .001 1&#93;.
<LI>Feed this scaled glyph to the second parameter of the module, which
puts glyphs on all the data points.
The module will use the squashed glyph as its template.
After the template is scaled by &#91;1 1 .001&#93;, the glyphs
won&#39;t be squashed anymore.

<LI>A macro, UnsquishGlyphMacro.net, which performs this operation, can
be found in <TT>/usr/share/dx/samples/macros</TT>. This macro (and this
technique) works only for scalar data.

</UL>
</TD></TR></TABLE>
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