I would like to suggest an addition of the fast hadamard transform to the following package:
org.apache.commons.math.transform The class would be called: FastHadamardTransformer *1. A concise description of the new feature/enhancement.* The new feature will implement the fast hadamard transform. *2. References to definitions and algorithms.* Definition of the hadamard transform: http://en.wikipedia.org/wiki/Hadamard_transform#Definition Unfortunately, Mathworld does not provide a very detailed definition. http://mathworld.wolfram.com/HadamardTransform.html An elegant algorithm for the fast hadamard transform can be found here: http://www.archive.chipcenter.com/dsp/DSP000517F1.html *3. Some indication of why the addition/enhancement is practically useful.* The hadamard transform has applications in signal processing and data compression.
