Grace is a nice program for graphing all sorts of data.


It is free and can be obtained from and installed quite easily (especially if you use the binary versions).


Once installed, it is useful to set the GRACE_HOME environment variable:


>export GRACE_HOME=/usr/local/grace                # or wherever it happens to be


and include the directory that contains the executable in your path:


>export PATH=$PATH:$ GRACE_HOME/bin


The documentation can be found at the above web site.