In this section, we provide precise mathematical definitions for the Chris@10: transforms that FFTW computes. These transform definitions are fairly Chris@10: standard, but some authors follow slightly different conventions for the Chris@10: normalization of the transform (the constant factor in front) and the Chris@10: sign of the complex exponent. We begin by presenting the Chris@10: one-dimensional (1d) transform definitions, and then give the Chris@10: straightforward extension to multi-dimensional transforms. Chris@10: Chris@10:
Chris@10: Chris@10: Chris@10: Chris@10: