Node:1d Discrete Hartley Transforms (DHTs), Next:Multi-dimensional Transforms, Previous:1d Real-odd DFTs (DSTs), Up:What FFTW Really Computes
The discrete Hartley transform (DHT) of a 1d real array X of size n computes a real array Y, where:
FFTW computes an unnormalized transform, in that there is no coefficient in front of the summation in the DHT. In other words, applying the forward and then the backward transform will multiply the input by n.