chatExcel

/* Translated from Cython into C++ by SciPy developers in 2023. * * Original author: Josh Wilson, 2016. */ #pragma once #include "config.h" namespace xsf { namespace detail { XSF_HOST_DEVICE inline std::complex<double> zlog1(std::complex<double> z) { /* Compute log, paying special attention to accuracy around 1. We * implement this ourselves because some systems (most notably the * Travis CI machines) are weak in this regime. */ std::complex<double> coeff = -1.0; std::complex<double> res = 0.0; if (std::abs(z - 1.0) > 0.1) { return std::log(z); } z -= 1.0; for (int n = 1; n < 17; n++) { coeff *= -z; res += coeff / static_cast<double>(n); if (std::abs(res / coeff) < std::numeric_limits<double>::epsilon()) { break; } } return res; } } // namespace detail } // namespace xsf