On Thursday, June 19, 2014 12:27:40 AM Alex wrote: > Actually, it is not really clear to me why `d` AKA `len` is needed at all, > since d = (size(A,dim[1])-1)<<1 appears to be well defined. I am probably > missing something here. Maybe Steven or someone else can clarify this?
Doc bug. The A referred to in this statement is the _original real-valued_ A. And the formula is wrong. A better way to write the help would be Base.irfft(Afft, d[, dims]) Inverse of "rfft()": for a complex array "Afft", gives the corresponding real array "A" whose FFT yields "Afft" in the first half. As for "rfft()", "dims" is an optional subset of dimensions to transform, defaulting to "1:ndims(Afft)". "d" is the length of the transformed real array along the "dims[1]" dimension, which must satisfy "size(Afft,dims[1]) == floor(d/2)+1". (This parameter cannot be inferred from "size(Afft)" due to the possibility of rounding by the "floor" function here.)
