On Sun, Aug 24, 2008 at 8:03 PM, Dan Lenski <[EMAIL PROTECTED]> wrote:
> Hi all, > Is there a good reason why the weights parameter of np.average() doesn't > broadcast properly? This is with the Ubuntu Hardy x86_64 numpy package, > version 1.0.4. > > > In [293]: a=arange(100).reshape(10,10) > > # Things work fine when weights have the exact same shape as a > > In [297]: average(a, axis=1, weights=ones((10,10))) > Out[297]: array([ 4.5, 14.5, 24.5, 34.5, 44.5, 54.5, 64.5, 74.5, > 84.5, 94.5]) > > # Bizarre and incorrect result with length-10 weight array > > In [298]: average(a, axis=1, weights=ones(10)) > Out[298]: > array([[[[[[[[[ 0., 1., 2., 3., 4., 5., 6., 7., 8., 9.], > [ 10., 11., 12., 13., 14., 15., 16., 17., 18., 19.], > [ 20., 21., 22., 23., 24., 25., 26., 27., 28., 29.], > [ 30., 31., 32., 33., 34., 35., 36., 37., 38., 39.], > [ 40., 41., 42., 43., 44., 45., 46., 47., 48., 49.], > [ 50., 51., 52., 53., 54., 55., 56., 57., 58., 59.], > [ 60., 61., 62., 63., 64., 65., 66., 67., 68., 69.], > [ 70., 71., 72., 73., 74., 75., 76., 77., 78., 79.], > [ 80., 81., 82., 83., 84., 85., 86., 87., 88., 89.], > [ 90., 91., 92., 93., 94., 95., 96., 97., 98., 99.] > ]]]]]]]]) > This has been fixed in later versions: In [2]: a=arange(100).reshape(10,10) In [3]: average(a, axis=1, weights=ones(10)) Out[3]: array([ 4.5, 14.5, 24.5, 34.5, 44.5, 54.5, 64.5, 74.5, 84.5, 94.5]) However, broadcasting in the axis=None case is not allowed. The thinking is that the weights must be fully specified for the axis (or None) that is being averaged over. Chuck
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