cosine_transform, a C code which demonstrates some simple properties of the discrete cosine transform (DCT) 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 MIT license
cosine_transform is available in a C version and a C++ version and a FORTRAN90 version and a MATLAB version and a Python version.
FFT_SERIAL, a C code which demonstrates the computation of a Fast Fourier Transform, and is intended as a starting point for implementing a parallel version.
HAAR, a C code which computes the Haar transform of data.
SFTPACK, a C code which implements the "slow" Fourier transform, intended as a teaching tool and comparison with the fast Fourier transform.
SINE_TRANSFORM, a C code which implements the discrete sine transform.
WALSH, a C code which implements versions of the Walsh and Haar transforms.
WAVELET, a C code which does some simple calculations with wavelet transforms;