A new look at the comparison of the fast Hartley and Fourier transforms

In the correspondence, a fair comparative analysis of algorithms for the fast Hartley transform (FHT) and the real valued fast Fourier transform (RVFFT) is presented. The complexity analysis and run-time comparisons are conducted and explained simultaneously. The complexity analysis shows great similarity between RVFFT and FHT. The run-time comparisons also show negligible differences, with some small advantages to RVFFT. The influence of the compiler on the execution time may be more significant than the choice of the algorithm. Also, a new and more accurate model for the prediction of execution time of the algorithm is proposed.