NAME
yacas, yacas_client — small and flexible general-purpose computer
algebra system
SYNOPSIS
yacas [options] [{filename}]
DESCRIPTION
This manual page documents briefly the yacas and yacas_client commands.
Yacas (Yet Another Computer Algebra System) is a small and highly
flexible general-purpose computer algebra language. The syntax uses a
infix-operator grammar parser. The distribution contains a small
library of mathematical functions, but its real strength is in the
language in which you can easily write your own symbolic manipulation
algorithms. The core engine supports arbitrary precision arithmetic,
and is linked with the GNU arbitrary precision math library, and is
able to execute symbolic manipulations on various mathematical objects
by following user-defined rules.
This manual page was written for the Debian GNU/Linux distribution
because the original program does not have a manual page.
OPTIONS
A summary of options is given below
-c Inhibit printing of prompts "In>" and "Out>". Useful for non-
interactive sessions.
-f Reads standard input as one file, but executes only the first
statement in it. (You may want to use a statement block to
have several statements executed.)
-p Does not use terminal capabilities, no fancy editing on the
command line and no escape sequences printed. Useful for non-
interactive sessions.
-t Enable some extra history recall functionality in console
mode: after executing a command from the history list, the
next unmodified command from the history list will be
automatically entered on the command line.
{filename}
Reads and executes commands in the filename and exits.
Equivalent to "Load()".
-v Prints version information and exits.
-d Prints the path to the Yacas library directory and exits
The default operation of Yacas is to run in the interactive console
mode. Yacas accepts several options that modify its operation. Options
can be combined.
In addition to the console mode, an experimental persistent session
facility is provided through the script yacas_client. By means of this
script, the user can configure third-party applications to pass
commands to a constantly running "Yacas server" and get output. The
"Yacas server" is automatically started by yacas_client. It may run on
a remote computer; in that case the user should have a user account on
the remote computer and privileges to execute yacas_client there, as
well as rsh or ssh access. The purpose of yacas_client is to enable
users to pass commands to Yacas within a persistent session while
running another application such as a text editor.
The script yacas_client reads yacas commands from the standard input
and passes them to the running "Yacas server"; it then waits 2 seconds
and prints whatever output yacas produced up to this time. Usage may
looks like this:
8:20pm Unix>echo "x:=3" | yacas_client
Starting server.
[editvi] [gnuplot]
True;
To exit Yacas, enter Exit(); or quit or Ctrl-c. Type ?? for help.
Or type ?function for help on a function.
Type ’restart’ to restart Yacas.
To see example commands, keep typing Example();
In> x:=3
Out> 3;
In> 8:21pm Unix>echo "x:=3+x" | yacas_client
In> x:=3+x
Out> 6;
In> 8:23pm Unix>yacas_client -stop
In> quit
Quitting...
Server stopped.
8:23pm Unix>
Persistence of the session means that yacas remembered the value of "x"
between invocations of yacas_client. If there is not enough time for
Yacas to produce output within 2 seconds, the output will be displayed
the next time you call yacas_client.
The "Yacas server" is started automatically when first used and can be
stopped either by quitting yacas or by an explicit option yacas_client
-stop, in which case yacas_client does not read standard input.
The script yacas_client reads standard input and writes to standard
output, so it can be used via remote shell execution. For instance, if
an account "user" on a remote computer "remote.host" is accessible
through ssh, then yacas_client can be used remotely like this:
echo "x:=2;" | ssh user@remote.host yacas_client
On a given host computer running the "Yacas server", each user
currently may have only one persistent Yacas session.
SEE ALSO
/usr/share/yacas/documentation/books.html (link to URL
file:/usr/share/yacas/documentation/books.html) or
http://www.xs4all.nl/~apinkus/manindex.html (link to URL
http://www.xs4all.nl/~apinkus/manindex.html) for more information.
AUTHOR
yacas was written by Ayal Pinkus (apinkus@xs4all.nl). yacas is
available at http://www.xs4all.nl/~apinkus/yacas.html (link to URL
http://www.xs4all.nl/~apinkus/yacas.html) .
This manual page was written by Gopal Narayanan (gopal@debian.org) for
the Debian GNU/Linux system (but may be used by others).
yacas(1)