Help with levin2d & fpm & stdlib

[freevryheid]

Late to the party - there’s also this:

DE quadrature module

I did not write this - only the wrapping for use with fpm. Useful for integration of oscillatory functions. I was looking for a replacement for quadosc in mpmath, after migrating to fortran A test is included to calculate the normal stress in a layer under a circular load - a bessel function.