Introduction
                                       
   This is the FAQ ("frequently asked questions") document for the Gri
   scientific graphing language, (c) 1991-2000 Dan Kelley
   (Dan.Kelley@Dal.Ca), to whom you are asked to email reports of
   Gri errors, or suggestions for Gri improvements or new features.
   
                                 The Questions
                                       
Q1 Features

     * Q1.1 What is Gri?
     * Q1.2 What does `Gri' stand for? How is it pronounced?
     * Q1.3 What does Gri cost?
     * Q1.4 How long will it take to learn Gri?
       
Q2 Documentation

     * Q2.1 Is there a quick-reference card for Gri?
     * Q2.2 Where can I get documentation for Gri?
     * Q2.3 Is there a cookbook of Gri program to use for guidance?
     * Q2.4 Is there a newsgroup for Gri?
     * Q2.5 Where can I get some sample Gri input files?
       
Q3 Can Gri do ... ?

     * Q3.1 Can Gri do barcharts?
     * Q3.2 Can Gri do histograms?
     * Q3.3 Can Gri do error bars?
     * Q3.4 Can Gri draw labels for Tukey box plots?
     * Q3.5 Can Gri read compressed data files?
     * Q3.6 Can Gri use scientific notation on axes?
     * Q3.7 Can Gri label x-axis with day of week?
     * Q3.8 Can Gri draw maps?
       
Q4 Gri and other programs

     * Q4.1 Is Gri better than Fortran/C/... plotting subroutines?
     * Q4.2 How can I include Gri plots in LaTeX files?
     * Q4.3 How may I convert Gri output to GIF format?
     * Q4.4 Is there an Emacs mode for Gri?
       
Q5 Evolution of Gri

     * Q5.1 Where can I get the latest version of Gri?
     * Q5.2 How can I find out the most recent features of Gri?
     * Q5.3 Should I keep my copy of Gri up-to-date?
     * Q5.4 How can I protect myself against changes to Gri?
       
Q6 Gri on various computers

     * Q6.1 What computers does Gri work on?
     * Q6.2 What kind of compiler is required to compile gri?
     * Q6.3 Why can't I link my compiled gri? (on HP computer)
     * Q6.4 Is there a Macintosh version of Gri?
     * Q6.5 Is there a DOS/Windows version of Gri?
     * Q6.6 Is there a linux version of Gri?
       
Q7 Gri bugs

     * Q7.1 What are known bugs in Gri?
     * Q7.2 How can I report Gri bugs?
       
                                  The Answers
     _________________________________________________________________
   
A1 Features

   
  A1.1 What is Gri?
  
   Gri is a program for drawing scientific graphs. It makes xy plots
   (linegraphs and scattergraphs), contour plots, and image plots. Unlike
   many scientific plotting packages, Gri provides precise control over
   fonts, line widths, grayscales, colors, etc. Since Gri was written by
   a scientist, it does the kinds of plots scientists want. It has few
   frills; e.g., it does not do 3D mesh plots, because the author
   dislikes them. Gri is command-driven, not mouse driven.
   
   
  A1.2 What does `Gri' stand for? How is it pronounced?
  
   Gri stands for `gr-interactive', and `gr' is the name of a subroutine
   library that preceded Gri. The `interactive' adjective indicates that
   Gri can be used interactively -- that is, Gri is an interpreted
   language whereas Gr is a compiled language. `Gri' rhymes with `try'.
   
   
  A1.3 What does Gri cost?
  
   Gri is free. A commercial version, called Gre (rhymes with `tree')
   will be made available soon. It contains most of Gri as a subset, but
   also contains quite a lot of the Perl language as well, making it a
   fully functional and efficient programming language.
   
   
  A1.4 How long will it take to learn Gri?
  
   Most users can get Gri working after spending half an hour with manual
   (see Q2.1). Familiarity with your operating system (for example
   for viewing PostScript files) will speed this somewhat. After that,
   it's best to learn new features only as you come to need them. To
   begin with, you should skim the manual and the cookbook (see
   Q2.3), looking just at the illustrations. This will take no more
   than an hour.
   
   The Gri manual is like most computer manuals: it would be a waste of
   time to read it cover to cover before starting to use Gri. But you'll
   find the manual helpful as you branch out, modifying the existing
   examples and inventing code of your own.
   
   Learning how to use a new command usually takes only a minute but
   realizing that the command exists can take longer. That's why many
   users with sophisticated needs find it useful to spend an afternoon
   leafing through the entire manual at some point.
   
   Most things in Gri can be done elegantly or crudely. The elegant
   approach may require a little investment in time at the beginning, but
   this will pay off constantly as your needs grow. For example, folks
   who like computer programming often start using Gri "newcommands" (a
   form of subroutines) within a few days. Other folks might avoid
   newcommands, instead putting their entire program in one long "main
   routine". What's right for you depends on how you think and the sort
   of work you do.
     _________________________________________________________________
   
A2 Documentation

   
  A2.1 Is there a quick-reference card for Gri?
  
   Yes, two quick-reference cards are stored on the FTP site
   ftp://ftp.phys.ocean.dal.ca/users/kelley/gri. The PostScript file
   refcard.ps is an overview of Gri syntax and usage, while cmdrefcard.ps
   is a full list of Gri commands. Each of these files is also available
   in TeX format.
   
   
  A2.2 Where can I get documentation for Gri?
  
   Full documentation is available in several forms on the FTP site
   ftp://ftp.phys.ocean.dal.ca/users/kelley/gri. Check out the FAQ
   file (which you are reading now), cmdrefcard.ps (a PostScript
   reference card listing all Gri commands), refcard.ps (a PostScript
   reference card overviewing Gri), and a file called something like
   gri_manual_2.051.tar.gz (which is a complete PostScript manual
   including figures). To save time and paper, you should look at the FAQ
   and the two reference cards first.
   
   The Gri manual is available on the WWW (world wide web) at the URL
   http://gri.sourceforge.net/gridoc/html/index.html .
   
  A2.3 Is there a cookbook of Gri programs to use for guidance?
  
   Yes, at the website
   http://gri.sourceforge.net/gri-cookbook/index.html 
   
   
  A2.4 Is there a newsgroup for Gri?
  
   Gri has several email-type and web-type forums for discussions.
   
   Until recently, the only such forum was a majordomo-based email list,
   to which one subscribed by sending to majordomo@phys.ocean.dal.ca
   a message containing just the two words subscribe gri, and to which
   one contributed by mailing to gri@phys.ocean.dal.ca.
   
   However, in summer 2000 Gri got a much better suite of newsgroups, on
   the SourceForge Gri site . Since these newsgroups are archived and
   threaded, they are a better resource than the majordomo group
   mentioned in the last paragraph.
   
   
  A2.5 Where can I get some sample Gri input files?
  
   You can get them from the anonymous FTP at
   ftp://ftp.phys.ocean.dal.ca/users/kelley/gri. It is in the
   compressed tarfile with the word 'example' contained in it. The file
   is compressed with the program "gzip," so you'll type
        gunzip gri-examples-2.1.10.tar.gz
        tar xvf  gri-examples-2.1.10.tar

   (where 2.1.10 will be changed to the current version number), and the
   tar program will create a directory called 'examples' which contains
   the example .gri programs and datafiles. The 'examples' directory also
   contains subdirectories with names that reflect computer names (e.g.,
   SGI, SUN4). To get run gri on all the examples, go into the
   appropriate subdirectory and type 'make examples'. For example:
        cd examples/SUN4
        make examples

   creates files examples/SUN4/example1.ps, examples/SUN4/example2.ps,
   etc.
     _________________________________________________________________
   
A3 Can Gri do ... ?

   
  A3.1 Can Gri do barcharts?
  
   Gri has no specific command for barcharts, but the operating system
   can easily rearrange your data into a form that lets Gri draw
   barcharts. In the following example, the synonym \width is set to the
   desired width of the bars and \missing is set to an arbitrary missing
   value. The rest of the code will make sense to any Perl programmer. If
   you don't know Perl, you should learn it.
\width = "1"                    // width of bars, in x units
\missing = "-99"                // missing value
set missing value \missing
set x axis 0 6 1
set y axis 0 20 10
draw axes none                  // will get whited out by the chart anyway

// Create dataset
system cat > barchart.dat << "EOF"
1 12
2 14
3 15
4 13
5 10
EOF

// Create barchart style dataset and plot it
system perl <<"EOF"
open (IN, "barchart.dat") || die "Cannot open barchart.dat";
while(<IN>) {
    ($x[$i], $y[$i]) = split(' ');
    $i++;
}
$n = $i;
open (TMP, ">tmp") || die "Cannot open tmp";
for ($i = 0; $i < $n; $i++) {
    print TMP $x[$i] - \width / 2, " ",      0, "\n";
    print TMP $x[$i] - \width / 2, " ", $y[$i], "\n";
    print TMP $x[$i] + \width / 2, " ", $y[$i], "\n";
    print TMP $x[$i] + \width / 2, " ",      0, "\n";
    print TMP \missing, " ", \missing, "\n";
}
EOF
open tmp
read columns x y
set graylevel 0.95
draw curve filled to 0 y
set graylevel 0
draw curve
draw axes
draw title "Demonstrate Gri barchart"


   
  A3.2 Can Gri do histograms?
  
   Gri has no specific command for histograms, but the operating system
   can easily rearrange your data into a histogram format.
   
   Here is Gri code to do it:
open "histogram -l 0 -h 10 -i 0.5 < inputfile |"
read columns x y // y is number of obs
draw curve filled to 0 y

   where histogram is a perlscript which creates a histogram file named
   inputfile. An example of histogram is:
#!/opt/bin/perl
# Calculate histogram of 1-column data
$usage ="\
NAME\
     histogram -- create histogram file, given data file (1 column)\
\
SYNOPSIS\
     histogram -l low -h high -i increment < input_file > output_file\
\
DESCRIPTION\
     Scans the input values and finds the percentage of data in bins\
     starting at value `low', ending at value `high', and incrementing by\
     value `inc'.\
\
FILES\
     Standard input:  column of numbers\
     Standard output: columns: (bin_centre, per, cum_per, num, cum_num)\
         where 'per'=percentage and 'num'=number.\
";
require "getopts.pl";
$opt_l = 0;
$opt_h = 0;
$opt_i = 0;
&Getopts('l:h:i:');
die "You must supply commandline arguments!\n$usage" if ($opt_l == $opt_h || $o
pt_i == 0);
$n = ($opt_h - $opt_l) / $opt_i;
print STDERR "Will have $n bins, running from $opt_l to $opt_h in steps of $opt
_i\n";
for ($i = 0; $i <= $n; $i++) {
    $bin[$i] = 0;
}
while(<>) {
    chop;
    ($x) = split;
    $i = int(0.5 + ($x - $opt_l) / $opt_i);
    $i =  0 if ($i < 0);
    $i = $n if ($i > $n);
    $bin[$i]++;
}
for ($i = 0; $i <= $n; $i++) {
    $x = $opt_l + $opt_i * ($i - 0.5);
    print "$x $bin[$i]\n";
    $x = $opt_l + $opt_i * ($i + 0.5);
    print "$x $bin[$i]\n";
}


   
  A3.3 Can Gri do error bars?
  
   Gri has no specific command for error bars. It has no internal
   representation of error bar data -- that is, you can't get them by a
   read columns command. However, you can get error bars quite easily,
   simply by reading the data line by line, plotting each one as
   individually. Here's an example of error bars in y, where the third
   column stores the error:
open a.dat
while 1
    read .x. .y. .ey.
    if ..eof..
        break
    end if
    draw symbol bullet at .x. .y.
    draw line from .x. {rpn .y. .ey. -} to .x. {rpn .y. .ey. +}
end while


   
  A3.4 Can Gri draw labels for Tukey box plots?
  
   Yes. Here is sample code, in which a label "My Label" is drawn to the
   right of the median of a Tukey plot extending in the y direction:
read columns x y
1 11
2 22
1.2 3
3 5
2 20
3 10

draw y box plot at 2
draw label "My Label" at {rpn 2 xusertocm 0.4 +} \
    {rpn y median yusertocm "M" ascent 2 / -} \
    cm


   
  A3.5 Can Gri read compressed data files?
  
   Yes, as of version 2.6 Gri can read compressed files, e.g.
    open myfile.gz
    read columns x y

   will work. You may also, of course, do
    open "zcat myfile.gz |"
    read columns x y

   if you like.
   

   
  A3.6 Can Gri use scientific notation on axes?
  
   You have to trick it. Here's an example:
// NOTE: this requires manual setting of axes.
read columns x y
1 1.1e3
2 1.0e3
3 1.4e3
4 2.3e3
4 1.0e4

y /= 1e3
set y axis 1 5 1
set y format "%g$\times10^3$"
draw curve


   
  A3.7 Can Gri label x-axis with day of week?
  
   A future version of Gri will have much more powerful and general ways
   of handling axes labelling. In the meantime, you have to trick Gri to
   get such special effects. Here's an example:
set x axis 1 8 1
set y axis 0 1 .1
set font size 0
draw x axis at top
draw y axis at right
draw x axis at bottom
set font size 12
draw y axis at left
draw label "Mon" centered at 1.5 {rpn ..ymargin.. 0.7 - ycmtouser}
draw label "Tue" centered at 2.5 {rpn ..ymargin.. 0.7 - ycmtouser}
draw label "Wed" centered at 3.5 {rpn ..ymargin.. 0.7 - ycmtouser}
draw label "Thu" centered at 4.5 {rpn ..ymargin.. 0.7 - ycmtouser}
draw label "Fri" centered at 5.5 {rpn ..ymargin.. 0.7 - ycmtouser}
draw label "Sat" centered at 6.5 {rpn ..ymargin.. 0.7 - ycmtouser}
draw label "Sun" centered at 7.5 {rpn ..ymargin.. 0.7 - ycmtouser}

   Note that the offset of 0.7 centimeters looks OK to me, with a 12
   point font, but you may wish to experiment if you don't like the
   placement.
   

   
  A3.8 Can Gri draw maps?
  
   Gri can draw maps, but it lacks builtin support for map projections.
   (A previous version had projections, but they were not working
   correctly and were removed.) Gri does not have builtin coastline
   files, either. Many good coastline files are on the web; see, for
   example, Rich Signell's site
       http://crusty.er.usgs.gov/coast/getcoast.html
   or the USGS mapping
   site 
       http://www.usgs.gov
   or the Global Self-consistent Hierarchical High-resolution
   Shoreline site
       http://www.ngdc.noaa.gov/mgg/shorelines/gshhs.html 
     _________________________________________________________________
   
A4 Gri and other programs

   
  A4.1 Is Gri better than Fortran/C/... plotting subroutines?
  
   Gri started out as a set of subroutines. The set is called `gr'; the
   name `gri' means gr-interactive. Although I wrote both `gr' and `gri',
   I haven't used gr in years. I am unaware of anybody else who ever used
   `gr'. Thus, in at least this case, the interpreted Gri language is
   superior to subroutines.
   
   In some applications the graphics are hard-wired into the computation
   so using Gri might not make sense. An example is the SPEM numerical
   model, which has builtin NCAR plotting calls. But this approach is
   inefficient in user-time and computer-time, because changing the
   format of the output may require re-running a model. The best approach
   is to decouple preparation of data from presentation of data.
   
   In highly interactive applications, such as many uses of matlab and
   statistical programs such as S and S-plus, it may make sense to use
   the builtin graphics routines because they are so tightly bound to the
   processing.
   
  A4.2 How can I include Gri plots in LaTeX files?
  
   This is done outside LaTeX (or TeX), with the program that converts
   from DVI format to PostScript format. This conversion is done
   differently on different computers; you'll have to enquire locally.
   With `dvips', you can use the `\special' command or the `\espfbox'
   command. The epsfbox command is smarter, since it figures the plot
   dimensions from the PostScript file itself. Unfortunately, old
   versions of Gri do not insert the correct plot dimensions in the
   PostScript file. Here's an example, for a 15cm tall figure, of how to
   insert a Gri PostScript file into a figure:
\documentstyle{article}
\begin{document}

... Figure \ref{fig1} shows ...

\begin{figure}
\vspace*{15cm}                  % MAKE ENOUGH SPACE
\special{psfile=fig1.ps}        % THIS INSERTS THE PLOT
\caption[Short caption, which appears in list of figures.]
{\label{fig1} Long caption, which appears with the figure.}
\end{figure}

\end{document}

   In other LaTeX and TeX dialects, of course (e.g. the lovely agu++
   format), you'll do things differently; the above will give you enough
   of a guide.
   

   
  A4.3 How may I convert Gri output to GIF format?
  
   Conversion of the Gri PostScript output to GIF is normally done for
   inclusion in web-pages. For a discussion of the merits of various
   image formats, see Information Architecture. I have been told that
   GIF images suffer from both technical limitations (no gamma value is
   stored in the file) and license restrictions. The PNG format was
   designed to overcome these limitations, and is expected to replace GIF
   before the year 2000.
   
   It should also be noted that there is no generally acceptable way to
   convert PostScript to gif, especially when the PostScript is vector
   based. One problem is that of resolution: if the output GIF is
   low-resolution, then the text may be drawn roughly because of
   rasterization. In many convertors one may specify the size of the
   output image, which permits control over this resolution problem,
   giving the user the task of weighing file size against output quality.
   Note also that the colour table frequently gets reordered in the
   conversion, possibly leading to inaccurate results. Simply stated,
   PostScript is superior to GIF and other raster-based formats. That's
   why Gri chose PostScript for the output model.
   
   There are several ways to convert Gri PostScript into GIF images.
     * METHOD 1. Use the convert program, which is a part of the
       ImageMagick set of software. The convert software is quite
       powerful, being able to convert from almost any format into almost
       any other. The ImageMagick software is free, and available on the
       world-wide-web at URL
           http://www.wizards.dupont.com/cristy/ImageMagick.html 
     * METHOD 2: The GNU program gs can also do this conversion. In newer
       versions, this conversion to GIF is builtin. Here is a shellscript
#!/usr/bin/sh
gri -y -p -b $1.gri
gs -q -dNOPAUSE -sDEVICE=ppm -sOutputFile=$1.ppm $1.ps -c quit
ppmtogif -interlace -transparent rgb:ff/ff/ff $1.ppm > $1.gif
rm -f $1.ppm
     * METHOD 3: In older versions of gs, you must run a little program
       in the gs interpreter, by typing
    $ gs foo.ps
    GS> (pstoppm.ps)run
    GS> (foo) ppm1run
    GS> quit
       This creates a file called foo.ppm, in the so-called PPM format.
       Various programs exist for converting image types, e.g. convert.
       
   Availability of software: ImageMagick uses Aladdin Ghostscript,
   another free program, to rasterize the PostScript file created by gri.
   Ghostscript is available from
       http://www.cs.wisc.edu/~ghost/index.html and many other sites
   (including any CTAN archive). Older version of ghostscript are
   available under the GNU GPL. Speaking of GNU, gs and other GNU
   software are freely available at many locations on the web, e.g.
       ftp://prep.ai.mit.edu/pub/gnu
   
   Author's note: this answer was compiled with advice from Peter
   Galbraith, Toru Suzuki, and George White, to each of whom I am very
   grateful for the help. In fact, the answer is mostly a patchwork of
   their suggestions, and all the helpful pointers to information on the
   web are theirs, not mine.
   

   
  A4.4 Is there an Emacs mode for Gri?
  
   Yes. Peter Galbraith has written a very powerful mode for Gri
   commandfiles which is supplied with Gri and which is fully documented
   in the manual. The capabilities of the mode include the following.
     * Indents loops, if statements, newcommands, etc.
     * Uses built-in knowledge of Gri commands to 'complete' your
       commands. For example, typing 'drM-TAB' (where M-TAB is the
       completion keystroke) causes the mode to write 'draw' in place of
       the 'dr'. Pressing M-TAB again gives a list of all Gri commands
       starting with 'draw'.
     * Provides complete access to Gri help on commands, including the
       full Gri 'info' manual if your machine has that installed. There
       is even an 'apropos' feature to let you search for commands you're
       not sure even exist.
     * Lets you run Gri from within the buffer. If syntax or runtime Gri
       errors are encountered, the cursor (usually) moves to the
       offending line in the Gri editing buffer.
     * Lets you run Ghostview without leaving Emacs.
     _________________________________________________________________
   
A5 Evolution of Gri


   
  A5.1 Where can I get the latest version of Gri?
  
   Gri is available at the anonymous FTP site
       ftp://ftp.phys.ocean.dal.ca/users/kelley/gri
   Instructions there will tell you what to do, but it should 
   be obvious if you've used FTP before.
   
   
  A5.2 How can I find out the most recent features of Gri?
  
   Do anonymous ftp to phys.ocean.dal.ca and cd to the directory
   /users/kelley/gri. Pick up the file ChangeLog. For more details, see
   the history chapter in the manual
   
  A5.3 Should I keep my copy of Gri up-to-date?
  
   The advantages of being up-do-date are:
     * You get new features.
     * There is a better chance of getting your bugs repaired, since all
       bug fixes are applied only to the current version.) The
       disadvantages of being up-to-date are:
     * You can get clobbered by new bugs. (You should avoid this by
       keeping your old versions of Gri. That means archiving both gri,
       the executable, and gri.cmd, the startup file.)
     * You can get clobbered by changes in the syntax. This is the
       penalty you pay for using a program under active development. To
       protect yourself, use the expecting version command, which will
       warn you of any incompatibilites between the version you expect
       and the version that is presently installed.
       
   Most people should not be more than 5-10 versions out of date. To keep
   in touch, subscribe to the gri maillist (...see Q2.3). Also, keep
   track of the file ChangeLog in the FTP location. As with most
   software, the supplier may be more enthusiastic about new versions
   than the users are. Other Gri users may therefore provide the best
   advice on whether it is worth upgrading.
   

   
  A5.4 How can I protect myself against changes to Gri?
  
   The most important thing is to save old versions of Gri. At hard-disk
   street prices of about a cent per megabyte, an archive will cost under
   a nickle.
   
   Archiving the source is just a matter of copying the files you've
   downloaded to a location of your choosing. Since the directory name is
   of the form gri-VERSION, keeping track of old sources is trivial.
   
   If you're using a prepackaged version of Gri (e.g. in RedHat or in
   Debian linux), then you'll probably know how to update Gri already. At
   any rate, you can skip some of the steps below, since rpm -ql gri will
   list all the relevant files, saving you the part of the steps below
   that involves locating files.
   
   Archiving the Gri binary and library file is quite easy, but archiving
   the documentation is complicated since there are a lot of
   documentation files, and they are scattered across your filesystem.
   For example, 'info' files go in the /usr/info directory, while
   'manpage' files go in the /usr/man/man* directory, and the 'html'
   files go someplace else). This isn't specific to Gri; the filesystem
   is just defined that way, for historical reasons. Your first step is
   to determine whether you wish to archive the documentation. In most
   case you won't want to. The point is just that you have an old set of
   scripts that you need to work; you won't be writing new scripts, and
   if you wrote these ones, then you understand Gri well enough anyway.
   Besides, Gri doesn't change that much from version to version, and the
   changes mostly involve additions.
   
   If you do wish to archive the documentation and emacs files, locate
   the files and copy them. (If you do not, skip the remainder of this
   paragraph.) In Redhat linux, do rpm -ql gri to locate the files. In
   debian linux, do something similar. If 'locate' is working on your
   computer, do locate gri and examine the list that you get. If none of
   the above is true, look in the second-last paragraph above for
   directories where Gri documentation files are often found, and move
   them to wherever seems appropriate. You'll probably have to alter
   other things as well, to tell the info and man programs where to find
   the documentation. If you use the Emacs editing mode, move that
   appropriately and edit whatever dot-files and system configuration
   files that Emacs uses to locate mode files. (Note that all emacs modes
   understand about using different versions; see the C-c C-r or by
   calling the command M-x gri-version. If, as is likely, you're only
   archiving Gri for old scripts that you don't need to edit, you may not
   need to worry about changes to gri-mode and you may as well go ahead
   and install the new gri-mode and forget about the old one.)
   
   If you only wish to archive Gri itself, things are much easier! You
   need to copy only two files, the executable (often /usr/bin/gri) and a
   library file (often /usr/share/gri/gri.cmd) to a directory of your
   choosing, and then create a shell alias (or a shellscript), which uses
   these two files you've copied. Let me take it step by step.
   
   First, type
    gri -version

   and make note of the present version number. For concreteness, let's
   say it is version 2.6.0.
   
   Next, decide where you wish to keep this gri version. For
   concreteness, let's say that you'd like to keep it in a directory
   named /usr/local/gri/2.6.0. Create that directory if it doesn't exist
   already:
    mkdir -p /usr/local/gri/2.6.0

   Next, type
    gri -directory_default

   to find out where the gri.cmd file is located. Let's say it's in the
   common location usr/share/gri, for concreteness; then you need to move
   this to your chosen directory:
    mv /usr/share/gri/gri.cmd /usr/local/gri/2.6.0

   Now, we need to copy the executable. If you don't know where it is,
   type
    which gri

   to find out. Then move it also, e.g. if Gri is located in the /usr/bin
   directory, you'd type
    mv /usr/bin/gri /usr/local/gri/2.6.0

   Now we just have to make an alias to run this particular copy of Gri,
   with this particular library file. In the Bash shell, just put the
   following line in your ~/.aliases file:
    alias gri2.6.0='/usr/local/gri/2.6.0/gri -directory /usr/local/gri/2.6.0'

   and then you have a new command, gri2.6.0 that runs this particular
   copy of Gri. Alternatively, you could create a shellscript to run this
   Gri, e.g. a script named gri2.6.0 that contains the lines:
    #!/usr/bin/sh
    # Run numbered version of gri
    /usr/local/gri/2.6.0/gri -directory /usr/local/gri/2.6.0 "$@"
     _________________________________________________________________
   
A6 Gri on various computers

   
  A6.1 What computers does Gri work on?
  
   Gri has been ported to several Unix machines (e.g. Sun solaris and
   sunOS; IBM RISC; HP RISC; SGI; DEC alpha; and x86 linux) and to x86
   MS-DOS. An old version is available for DEC vax VMS.
   
   
  A6.2 What kind of compiler is required to compile gri?
  
   Gri requires a C++ compiler capable of handling the language feature
   called "templates," and it also needs the so-called "standard template
   library" (STL). Templates have been a feature of C++ since about 1994,
   and STL became part of the draft C++ library standard in early 1996.
   If your compiler vendor does not support templates or STL, you should
   obtain a newer compiler.
   
   The free C++ compiler called g++, available from the Free Software
   Foundation, is known to compile Gri on at least a half-dozen problems.
   The compiler version must be 2.7.2 or higher for success.
   
   
  A6.3 Why can't I link my compiled gri? (on HP computer)
  
   Unfortunately, I made a bad programming decision several versions ago
   -- I decided to start using the STL (the standard template library).
   The STL is part of the draft ANSI C++ standard, so I figured I'd be
   safe. And my tests on solaris and linux platforms indicated that STL
   worked as advertised, in g++ 2.7.x. However, I should have checked
   further. It turns out that g++ on some platforms (e.g. HP's unix and
   IBMRS's AIX unix) does not handle templates properly. The linker
   cannot locate templates defined in one file and used in another. This
   issue is discussed at some length in the g++ documentation, where
   three methods are presented for solving the problem. (In the
   info-format documentation, you can find the relevant parts by
   searching for the string "where's the template?") In Gri I've used
   what method 3 as defined in the g++ manual. Apparently this fails on
   some platforms. Although I'd welcome tests by users on the other two
   g++ methods, and I'd be happy to switch if one of them appeared to
   work more universally, I have to say that I'm not optimistic: from
   what I read on the newsgroups, nobody is having much success on this.
   The GNU folks say that g++ version 2.8 will handle templates much
   better, so I'm waiting for that. Unfortunately it's been, so far, a
   two-year wait.
   
   Almost certainly, commercial compilers handle templates better, but I
   lack resources to purchase these for the various platforms. I'd be
   happy, though, to act as a broker for anyone who is able to compile
   Gri on the problematic platforms, and who is willing to share their
   results.
   
   
  A6.4 Is there a Macintosh version of Gri?
  
   There once was a clicky-pointy Macintosh version of gri, but I got
   frustrated with modifying the code each time Apple upgraded the OS and
   stopped maintaining the code. After several years of living (happily)
   without the Macintosh, I flushed the Mac code down the drain.
   
   However a version for Macintosh unix is available .
   
   
  A6.5 Is there a DOS/Windows version of Gri?
  
   There is a version available for DOS, available at the normal Gri FTP
   site, 
       ftp://ftp.phys.ocean.dal.ca/users/kelley/gri
   and copy another at the anonymous FTP site
       ftp://shiho.tokyo-u-fish.ac.jp/pub/msdos/gri
   with filename of the form gri2025b.zip where 2025 refers
   to the version name. This binary version was prepared and
   very kindly shared by Toru Suzuki 
       toru@shiho.tokyo-u-fish.ac.jp
   Together with the distribution comes a file called README, 
   which tells how to install and use Gri in an msdos context.
   
   Also, see the Gri manual under the heading Compilation on x86
   (PC-style) Computers
   
   As for viewing the output, I recommend obtaining a copy of the
   Ghostview program (which is a general PostScript display program), in
   the version called GSview.
   

   
  A6.6 Is there a linux version of Gri?
  
   For non-RedHat versions of linux, one compiles and installs Gri in the
   usual way; see the manual for more details.
   
   Users of RedHat linux have it much easier though! A RPM (RedHat
   Program Manager) version of Gri exists, so that installing it takes
   just one line of typing, or one mouse-click in the RPM GUI-based
   installer called `glint'. requires just one line of typing.
   
   The RPM (RedHat Package Manager) version exists at FTP site
       ftp://ftp.phys.ocean.dal.ca/users/kelley/gri 
   in a file with a name such as `gri-2.1.17-1.i386.rpm' 
   (RedHat readers will know immediately what all the numbers and dots
   stand for!) Once you've downloaded this, install Gri by typing
       rpm -i gri-2.1.17-1.i386.rpm

   Later on, Gri may be uninstalled ('extracted') by typing
       rpm -e gri

   Knowledgeable RedHat users will know that RPM can also give
   information about Gri; for non-experts, here are a few examples:
       rpm -qa       --  list all installed packages
       rpm -qi gri   --  summarize gri capabilities (if it's installed)
       rpm -ql gri   --  list all files related to gri
     _________________________________________________________________
   
A7 Gri bugs

   
  A7.1 What are known bugs in Gri?
  
   Gri is used daily by many users, including the author, so that it
   suffers few serious bugs. Generally, more recent versions of Gri
   suffer fewer bugs than earlier versions. This improvement owes much to
   the trial of daily usage by folks with differing working styles; and
   all users can thank those who send in bug reports (see Q7.2).
   
   One of the main problems with recent versions of Gri is that line
   numbers of syntax errors are reported inaccurately, if the error
   occured inside a new-command.
   
   A list of Gri bugs is maintained in the manual.
   

   
  A7.2 How can I report Gri bugs?
  
   The first step is to make sure it is actually a bug. You might try,
   for example, posting a question to the Gri newsgroup (see Q2.3),
   and getting advice from other users. Please be clear, so you don't
   waste others users' time. If you think you've found a bug, let the
   author know. Here's the advice from the manual (see especially item 4,
   for directions on emailing bug reports):
   
   Your bug reports help make Gri reliable and useful. Reporting bugs
   often results in quick changes to gri which will solve your problem.
   This is especially true if your version is reasonably up-to-date, for
   then you can simply get the corrected version and replace the version
   you were using. Here is how to report bugs.
   
   The details of how to report bugs is in the online documents ,
   but the quick answer is to go to the Sourceforge Gri/bug site and
   use the slick GUI interface there.

References

   1. http://www.phys.ocean.dal.ca/~kelley
   2. mailto:Dan.Kelley@Dal.Ca
   3. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#A1.1
   4. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#A1.2
   5. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#A1.3
   6. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#A1.4
   7. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#A2.1
   8. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#A2.2
   9. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#A2.3
  10. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#A2.4
  11. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#A2.5
  12. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#A3.1
  13. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#A3.2
  14. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#A3.3
  15. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#A3.4
  16. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#A3.5
  17. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#A3.6
  18. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#A3.7
  19. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#A3.8
  20. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#A4.1
  21. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#A4.2
  22. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#A4.3
  23. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#A4.4
  24. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#A5.1
  25. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#A5.2
  26. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#A5.3
  27. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#A5.4
  28. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q6.1
  29. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q6.2
  30. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q6.3
  31. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q6.4
  32. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q6.5
  33. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q6.6
  34. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#A7.1
  35. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#A7.2
  36. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q1.1
  37. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q1.2
  38. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q1.3
  39. http://www.phys.ocean.dal.ca/~kelley/gre
  40. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q1.4
  41. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q2.1
  42. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q2.3
  43. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q2.1
  44. ftp://ftp.phys.ocean.dal.ca/users/kelley/gri
  45. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q2.2
  46. ftp://ftp.phys.ocean.dal.ca/users/kelley/gri
  47. http://gri.sourceforge.net/gridoc/html/index.html
  48. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q2.3
  49. http://gri.sourceforge.net/gri-cookbook/index.html
  50. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q2.4
  51. mailto:majordomo@phys.ocean.dal.ca
  52. mailto:gri@phys.ocean.dal.ca
  53. http://sourceforge.net/forum/?group_id=5511
  54. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q2.5
  55. ftp://ftp.phys.ocean.dal.ca/users/kelley/gri
  56. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q3.1
  57. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q3.2
  58. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q3.3
  59. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q3.4
  60. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q3.5
  61. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q3.6
  62. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q3.7
  63. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q3.8
  64. http://crusty.er.usgs.gov/coast/getcoast.html
  65. http://www.usgs.gov/
  66. http://www.ngdc.noaa.gov/mgg/shorelines/gshhs.html
  67. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q4.1
  68. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q4.2
  69. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q4.3
  70. http://www.lanl.gov/projects/ia
  71. http://www.wizards.dupont.com/cristy/ImageMagick.html
  72. http://www.cs.wisc.edu/~ghost/index.html
  73. ftp://prep.ai.mit.edu/pub/gnu
  74. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q4.4
  75. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q5.1
  76. ftp://ftp.phys.ocean.dal.ca/users/kelley/gri
  77. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q5.2
  78. http://gri.sourceforge.net/gridoc/html/History.html
  79. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q5.3
  80. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q2.3
  81. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q5.4
  82. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q6.1
  83. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q6.2
  84. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q6.3
  85. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q6.4
  86. http://gri.sourceforge.net/gridoc/html/mac-install.html#Mac-install
  87. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q6.5
  88. ftp://ftp.phys.ocean.dal.ca/users/kelley/gri
  89. ftp://shiho.tokyo-u-fish.ac.jp/pub/msdos/gri
  90. mailto:toru@shiho.tokyo-u-fish.ac.jp
  91. http://gri.sourceforge.net/gridoc/html/msdos-install.html#Msdos-install
  92. http://www.cs.wisc.edu/~ghost/index.html
  93. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q6.6
  94. http://gri.sourceforge.net/gridoc/html/index.html
  95. ftp://ftp.phys.ocean.dal.ca/users/kelley/gri
  96. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q7.1
  97. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q7.2
  98. http://gri.sourceforge.net/gridoc/html/KnownBugs.html#KnownBugs
  99. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q7.2
 100. file://localhost/home/kelley/GRI-work/gri/doc/FAQ.html#Q2.3
 101. http://gri.sourceforge.net/gridoc/html/ReportingBugs.html#ReportingBugs
 102. http://sourceforge.net/bugs/?group_id=5511