Bessel functions for complex numbers

[miklos1]

There is apparent demand for using Bessel functions in complex-values PDEs, however, is there a C or C++ implementation available somewhere? Quasi-standard C libraries have j0, j1, jn, y0,
y1, and yn, but only for reals. The Boost implementation is templated, but uses comparisons, therefore do not work when instantiated with complex numbers.

[wence-]

AFAICT, the whole world uses the implementation from here: https://dl.acm.org/citation.cfm?doid=7921.214331

A C++ wrapper is available here: https://blog.joey-dumont.ca/complex_bessel/