Dear all, I found a link to the Numerical Mathematics Consortium http://www.nmconsortium.org/index.aspx Their rationale can be summarized (as far as I understood) by the paragraphs which I copied from their homepage and pasted below. Maybe this could be of interest also for the development of R? Best, Roland And here the copy+paste from their homepage: As modern numerical programming languages have replaced FORTRAN as the language of choice, and as new interactive design and development tools were introduced over the years, the standardized representation of common functions began to disperse again. The problem is as simple as looking at the Fast Fourier Transform (FFT) function: Mathcad t := 0..127 x := sin(2.p..01.t) w :=fft(x) MATLAB t = 0:127 x = sin(2*pi*.01*t) w = fft(x) Size of w: Mathcad = 65 MATLAB = 128 As in this case, even if the syntax is identical, the calculations yield different results! By definition, the FFT function of real data produces a result where the second half of the data is the complex conjugate of the first half. Mathcad uses this and only returns the first half of the data (i.e. N/2 + 1). MATLAB returns all of the data (N). Both are valid interpretations. The Numerical Mathematics Consortium is proposing a semantic standard for core numerical functions so as to help solve issues such as this. +++++ This mail has been sent through the MPI for Demographic Rese...{{dropped}}