In article <mailman.465.1347307911.27098.python-l...@python.org>, MRAB <python-list@python.org> wrote: >On 10/09/2012 20:39, Wanderer wrote: >> >> I have an array generated by audiolab of left and right stereo >> channels. It looks like [[1,1],[1,2],[2,3]]. I would like to combine >> the left and right channels to get an array [2,3,5]. Is there a numpy >> command to do that? > >>>> import numpy >>>> numpy.array([[1,1],[1,2],[2,3]], dtype="i") >array([[1, 1], > [1, 2], > [2, 3]]) >>>> a[:, 0] >array([1, 1, 2]) >>>> a[:, 1] >array([1, 2, 3]) >>>> a[:, 0] + a[:, 1] >array([2, 3, 5]) > >But should they be added together to make mono? > >Suppose, for example, that both channels have a maximum value. Their >sum would be _twice_ the maximum. > >Therefore, I think that it should probably be the average. > > >>> (a[:, 0] + a[:, 1]) / 2 >array([1, 1, 2])
I'd actually think it should be the max. Consider a stereo where one side is playing a booming bass while the other side is playing a rest note -- should the mono combination be half as loud as as the bass? -- Aahz (a...@pythoncraft.com) <*> http://www.pythoncraft.com/ "....Normal is what cuts off your sixth finger and your tail..." --Siobhan -- http://mail.python.org/mailman/listinfo/python-list
