SINE_TRANSFORM is a Python library which demonstrates some simple properties of the discrete sine transform for real data.
The code is not optimized in any way, and is intended instead for investigation and education.
The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.
SINE_TRANSFORM is available in a C version and a C++ version and a FORTRAN90 version and a MATLAB version and a Python version.
COSINE_TRANSFORM, a Python library which demonstrates some simple properties of the discrete cosine transform for real data.
SFTPACK, a Python library which implements the "slow" Fourier transform, intended as a teaching tool and comparison with the fast Fourier transform.
You can go up one level to the Python source codes.