Original ticket http://projects.scipy.org/numpy/ticket/1545 on 2010-07-15 by trac user dgoldsmith, assigned to unknown.

Presently, the fft functions return the unscaled transform and the ifft functions return the (1/n)-scaled inverse transform, meaning that neither result is unitary. In contrast, the discrete cosine transform (DCT) functions in scipy.fftpack include a keyword argument (norm) which, when set to "ortho," normalize both the forward and inverse transforms (both functions have the keyword argument) by 1/sqrt(n), thus returning unitary results. There appears to be no reason why the fft functions couldn't also support this.