yorick - interpreted language for numerical analysis and postprocessing
[ -i file1.i
[ -i file2.i
[ ... ]]]
is an interpreted language like Basic or Lisp, but far faster. It
- A C-like language, but without declarative statements. Operations between
arrays produce array results, which is one reason for Yorick's high
- An X window system interactive graphics package. Concentrates on x-y plots
and filling and contouring quadrilateral meshes. Also handles cell arrays.
Graphics can be output to binary CGM or PostScript files as well. A
separate CGM browser, gist(1), is included.
- A binary file package which can read or write floating point formats which
are foreign to the machine where Yorick is running. Thus, you can share
binary files freely on a heterogeneous network.
- A library of functions written in the Yorick language. These include
Bessel, gamma, and related functions, multiple key sorting, spline,
rational function, and least squares fitting, and routines to read and
write netCDF files.
- Provisions for embedding compiled subroutines and functions within a
Yorick interpreter. A compiled package which solves matrices and performs
FFTs is supplied.
You cannot learn to program in Yorick by reading this man page. Instead, start
Yorick (with no arguments) and type: help
This will tell you the name of the Yorick site directory
at your site.
The site directory contains a doc/ subdirectory; read the README file there to
find out about more documentation. The Yorick user manual is in project GNU's
TeXinfo format, which can be either printed or read online as hypertext using
the info command in GNU Emacs. Also available are a set of six quick reference
sheets (as PostScript), and alphabetized collections of all of Yorick's online
help comments (accessible via the help command). Finally, the i/ subdirectory
of the Yorick site directory is a library of functions which are written in
the Yorick language, which are also helpful as examples of how to write Yorick
To demonstrate Yorick, start Yorick and type the following two lines: #include
After the little movie runs on your X window system display, try: help, demo1
Follow the SEE ALSO references in this help message by issuing additional help
commands. Also, the help command will print the full pathname of the demo1.i
file. Read this file to see how the demo1 function works. You can repeat this
procedure with demo2.i, demo3.i, and demo4.i: demo1 - movies of sound and
shock waves demo2 - movies of a drumhead oscillating demo3 - movie of a
chaotic pendulum demo4 - visualization of the flow field around an airfoil
You can run a crude tutorial introducing all of the Yorick graphics commands by
starting Yorick and typing: #include "testg.i" grtest
You can get a description of the various files in the interpreted library by
typing (as a command to Yorick): library
- -i file.i
- includes the Yorick source file file.i as Yorick starts. This is
equivalent to the #include directive after Yorick has started.
- -batch file.i
- includes the Yorick source file file.i as Yorick starts. Your
customization file custom.i, if any, is not read, and Yorick is
placed in batch mode. Use the help command on the batch function (help,
batch) to find out more about batch mode. In batch mode, all errors are
fatal; normally, Yorick will halt execution and wait for more input after
David H. Munro, Lawrence Livermore National Laboratory
Y_SITE refers to the Yorick site directory; use the help command to find its
name at your site (the variable Y_SITE also contains the name of the site
- documentation, including the quick reference sheets, user manual, and
alphabetized collections of all the online help messages.
- a library of interpreted Yorick functions. Here are Bessel, gamma, and
beta functions, multiple key sorting, curve fitting functions, and more.
The file readme.i has a more complete description.
- graphics style sheets, palettes, and PostScript template
- include files Yorick needs to read whenever it starts. Several of these
contain the definitions of functions which you may need to read in order
to fully understand their operation, or as examples of Yorick
If x is a scalar int, long, or double, x(1)= scalar-expression
will fail. You normally wouldn't do the assignment like this (you would just
redefine x). Usually, you can work around this bug using the merge function;
do "help, merge" and read Y_SITE/i/bessel.i for examples of the
Expressions like openb("file_containing_x").x do not work, even though
they are syntactically and logically correct. It turns out the file closes
before the data can be read. This one may be fixable, but it's not easy.
The nice= and restrict= keywords to the limits function don't seem to work
Clipping of filled mesh plots (the plf command) is not always correct.
Text -- particularly curve markers -- is clipped by not drawing it; the absence
of partial characters at the edge of a plot puzzles most people.
Recursive debug mode (debugging an error which occurred while you were
debugging) doesn't work. Also, Yorick can't always get into and out of its
debug mode properly. Occasionally, it will get the line number where an error
occurred wrong, especially if the error was in the condition or increment
clause of a for loop.
On pseudocolor displays, a color image may require you to move the mouse into
yorick's X window to display properly, if you use the private=1 option of the
window command. Unless your window manager allows you to set colormap focus
independently of keyboard focus, this can be annoying.