(I'm not sure this is the right forum.)

I'm writing a program that uses the prime-counting function. Right now, I'm using x/log(x), but I want to switch to something more accurate. A better approximation is the logarithmic integral function (actually, its Eulerian variant), which can be computed from the exponential integral. Now how can I compute the exponential integral? I'm on a macOS Intel system using Swift, so I can use the various advanced floating-point functions provided by Apple's system libraries if needed to help.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.