One-dimensional Real-to-half-complex/Half-complex-to-real FFTs

Half-complex representation of a conjugate-even symmetric vector of size N in a real array of the same size N consists of N/2+1 real parts of the elements of the vector followed by non-zero imaginary parts in the reverse order. Because the Intel® oneAPI Math Kernel Library FFT interface does not currently support this representation, all wrappers of this kind are empty and do nothing.

Nevertheless, you can perform one-dimensional real-to-complex and complex-to-real transforms using rfftwnd functions with rank=1.