I frequently have the problem that I have to perform some simplistic calculations, mostly products and sums of two or three quantities. I used to use the
fp package for it, but it does look somewhat unmaintained. Now I've tried
pgfmath, and like everything coming from the TikZ direction it is outrageously complete, thoroughly documented, and has a nice API with a great syntax to top it off. And I'm using TikZ for graphics anyway, so there's no additional overhead in terms of packages used.
The only thing that worries me is performance. I could devise some tests to get a better idea of how fast
pgfmath is in comparison, but I thought I'd better ask around first:
are there any articles that compare different solutions to perform simple arithmetics in TeX
that include benchmarks?
What is the best practice when one wants to do multiplication of fractional, signed numbers? Neither precision nor magnitude have to be all that great, given that these numbers are used to do typesetting, so everything that is accurate to the tenth of a millimeter or so for dimensions up to several hundreds of millimeters should be fine.