FFTW is a free collection of fast C routines for computing the Discrete Fourier Transform in one or more dimensions. It includes complex, real, symmetric, and parallel transforms, and can handle arbitrary array sizes efficiently. FFTW is typical

此代码是依据《SUPERCONTINUUM GENERATION IN OPTICAL FIBERS》而来，利用分步傅里叶法和龙格库塔方法来求解广义非线性薛定谔方程