JAMA Matrix performance

Question

First of all, sorry for my bad English, but I need your help.

I have developed a simulation program with java swing where I have used lots of matrix calculations. My program is just finished but I need to speed up my performance. So I have used the java visual vm profiler to identify performance problems. I recognized that the initialization of Jama Matrices needs a lot of time. After running my program I had over 3 MB allocated Objects by JAMA. That's a lot of, isn't it? I think that's why the performance is bad.

Is there any better library than jama for matrices? I am using 3x3 matrices and I need multiplication and inverse operations or is there anything else i can do?

@blueArrow Please see [this SO question](http://stackoverflow.com/questions/529457/performance-of-java-matrix-math-libraries?rq=1) — Alexey Odintsov, Aug 23 '13 at 08:55
@hexafraction what do you mean with your question? i use the JAMA library. — blueArrow, Aug 23 '13 at 09:00
@AlexeyOdintsov i saw that question but it didn't helped me so far. — blueArrow, Aug 23 '13 at 09:01

score 1 · Answer 1 · edited May 23 '17 at 11:49

Usually matrix math libraries are not optimized for speed on small matrices. You can see for yourself by taking a few stackshots, which are liable to show a large fraction of time in overhead functions like memory allocation and option checking.

What you can do instead (which I've done) is write special-purpose routines to do the multiplication and inverse, since you know the matrices are 3x3. Multiplication is trivial and you can unroll the whole thing.

Inverse of a 3x3 matrix can also be done in less code than coffee :) Wikipedia gives you the formula.

Whatever you do, try to minimize memory allocation.

JAMA Matrix performance

1 Answers1