COSINE_TRANSFORM
A Discrete Cosine Transform for Real Data

COSINE_TRANSFORM is a MATLAB library 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.

Licensing:

The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.

Languages:

COSINE_TRANSFORM is available in a C version and a C++ version and a FORTRAN90 version and a MATLAB version and a Python version.

Related Data and Programs:

cosine_transform_test

FFT_SERIAL, a MATLAB program which demonstrates the computation of a Fast Fourier Transform, and is intended as a starting point for implementing a parallel version.

HAAR, a MATLAB library which computes the Haar transform of data.

SFTPACK, a MATLAB library which implements the "slow" Fourier transform, intended as a teaching tool and comparison with the fast Fourier transform.

SINE_TRANSFORM, a MATLAB library which implements the discrete sine transform.

WALSH, a MATLAB library which implements versions of the Walsh and Haar transforms.

WAVELET, a MATLAB library which does some simple calculations with wavelet transforms;

Reference:

1. William Briggs, Van Emden Henson,
   The DFT: An Owner's Manual for the Discrete Fourier Transform,
   SIAM, 1995,
   ISBN13: 978-0-898713-42-8,
   LC: QA403.5.B75.
2. Eleanor Chu, Alan George,
   Inside the FFT Black Box,
   CRC Press,
   ISBN: 0849302706,
   LC: QA403.5C5.

Source Code:

• r8vec_uniform_01.m, fills an R8VEC with unit uniform pseudorandom numbers.
• cosine_transform_data.m, does a cosine transform on a vector of data.
• cosine_transform_inverse.m, does an inverse cosine transform on a vector of cosine transform coefficients.
• timestamp.m, prints the current YMDHMS date as a time stamp.