inverse conjugates the twiddles and divides by n, so a forward transform followed by an
inverse one returns the input to within float noise — the round trip its test asserts. Both
arrays are read AND written.
Returns false and leaves the arrays untouched when the shape is not a power of two or the two
halves disagree in length. Absence is a fact: a caller that ignores the answer gets no
transform rather than a silently wrong one.
Transform
re/imin place, lengthn = re.length.inverseconjugates the twiddles and divides byn, so a forward transform followed by an inverse one returns the input to within float noise — the round trip its test asserts. Both arrays are read AND written.Returns false and leaves the arrays untouched when the shape is not a power of two or the two halves disagree in length. Absence is a fact: a caller that ignores the answer gets no transform rather than a silently wrong one.