cmgrowell on Nostr: I learned it to 7 digits in engineering school. Now I write geometry creation related ...

I learned it to 7 digits in engineering school. Now I write geometry creation related software for computational physics solvers and we have it set to 20 digits. The applications people don't like it if there are geometry inaccuracies when they are creating cell sizes in the 1e-6 or smaller range. Usually the issue is not PI, it is the sampling rate used to create the b-spline arc, etc. But, I don't want to introduce any other sources of possible error. The Fortran people would define it as a constant at the top of every file, and it would often be a different precision in each file.