On Sat, Mar 13, 2010 at 4:45 AM, Fabrice Silva <si...@lma.cnrs-mrs.fr> wrote: > Le samedi 13 mars 2010 à 10:20 +0100, Nicolas Rougier a écrit : >> Hello, >> I'm trying to translate a small matlab program for the simulation in a >> 2D flow in a channel past a cylinder and since I do not have matlab >> access, I would like to know if someone can help me, especially on >> array indexing. The matlab source code is available at: >> http://www.lbmethod.org/openlb/lb.examples.html and below is what I've >> done so far in my translation effort. >> >> In the matlab code, there is a "ux" array of shape (1,lx,ly) and I do >> not understand syntax: "ux(:,1,col)" with "col = [2:(ly-1)]". If >> someone knows, that would help me a lot... > > > As ux 's shape is (1,lx,ly), ux(:,1,col) is equal to ux(1,1,col) which > is a vector with the elements [ux(1,1,2), ... ux(1,1,ly-1)]. > Using ":" juste after the reshape seems a lit bit silly...
Except that python uses 0-based indexing and does not include the last number in a slice, while Matlab uses 1-based indexing and includes the last number, so really: ux(:,1,col) becomes: ux(0, 0, col) # or ux(:, 0, col) And if col is col = [2:(ly-1)] This needs to be: col = np.arange([1, ly - 1) Ryan -- Ryan May Graduate Research Assistant School of Meteorology University of Oklahoma _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion