symmat

I wrote a symbolic matrix manipulation program called "symmat". It allows you to use matrices with both numbers and variables, and get a reasonable matrix multiply (for example) out of it. I wrote it when I was taking a computer graphics course, long before I'd heard of anything like "matlab" and clones; the idea actually seemed novel at the time. You can get the source code here. Sample input looks like this:

push 4 4
1  0 0 0
0  c s 0
0 -s c 0
0  0 0 1

push 4 3
d 0 -t
0 1  0
t 0  d
0 0  0

mult
pop

As you can perhaps tell, it's stack-based (uses reverse-polish notation). "pop" displays the matrix on the top of the stack on stdout. Output for the above file looks like:

d   0  -t  
s*t c  s*d 
c*t -s c*d 
0   0  0

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Timestamp: 2025-01-09 18:15:44 PST

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