Changing values of 1st column of a matrix using take(mymatrix, (0, ),axis=1)

Discussion in 'Python' started by Anthony Liu, Feb 21, 2006.

  1. Anthony Liu

    Anthony Liu Guest

    I am talking about the 'take' method of numarray.

    See here for more info:

    http://stsdas.stsci.edu/numarray/Doc/node33.html

    If I initialize a matrix 'mymatrix' by zeros((3,3),
    type="Float64"), I get a 3*3 matrix of all zeros.

    Look:
    array([[ 0., 0., 0.],
    [ 0., 0., 0.],
    [ 0., 0., 0.]])
    I want to change the zeros of only the first column to
    1's. In other words, I want to get:

    array([[ 1., 0., 0.],
    [ 1., 0., 0.],
    [ 1., 0., 0.]])

    The 'take' method is able to take out the first
    column, but I am not sure if there is a good way of
    changing all values of the first column to 1's.

    Of course, I know that I can achieve my goal pretty
    easily with this:

    for i in range(3): mymatrix[i,0] = 1.0

    I am just wondering if there is an existing numarray
    method that elegantly does it for me.


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    Anthony Liu, Feb 21, 2006
    #1
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