I installed the rpm 'pgcalc' from the repositories, but I cannot find
any documentation anywhere that tells how to run it. I tried to type in
pgcalc on a command line, and the command is not found.

I tried going to the /opt/kde3/bin directory, where the program is
stored, and I ran this command, and here also is the result:

$:/opt/kde3/bin> ./pgcalc
pgcalc: cannot connect to X server
Any ideas on how to get this program to run? I need a scientific
calculator that can do calculations on complex numbers, and pgcalc also
has the advantage that it follows reverse polish notation. So it seems
like pgcalc is the application to go with, if I can get it started.

Box #1: 12.3 | KDE 4.10 | AMD Phenom IIX4 | 64 | 16GB
Box #2: 12.2 | KDE 4.9.2 | AMD Athlon X3 | 64 | 4GB
Laptop: 12.3 | KDE 4.10 | Core i7-2620M | 64 | 8GB
learning openSUSE and loving it