[SciPy-user] strange ValueError in scipy_core

Chris Fonnesbeck fonnesbeck at gmail.com
Thu Nov 10 14:29:07 CST 2005


I am converting some code over to scipy_core which involves populating
a relatively sparse matrix, so I am generating an array of zeros, and
substituting the non-zero elements. However, this substitution does
not seem to be allowed. Here is the relevant section of code.

           # Initialize projection matrix
            matrix = zeros((10,10),typecode='d')

            # Populate with non-zero elements
            matrix[0,4] = 0.5*s1
            matrix[1,0] = s2
            matrix[2,1] = s3
            matrix[3,2] = s4*(1.-g4)
            matrix[3,3] = sP*(1.-gP)
            matrix[4,2] = s4*g4
            matrix[4,3] = sP*gP
            matrix[4,5] = sA*gB
            matrix[5,4] = sA
            matrix[5,5] = sA*(1.-gB)
            matrix[6,4] = 0.5*s1
            matrix[7,6] = s2
            matrix[8,7] = s3
            matrix[9,8] = s4
            matrix[9,9] = sA

But I get the following:

--> 777             matrix[0,4] = 0.5*s1
        matrix = [[ 0., 0., 0., 0., 0., 0., 0., 0., 0., 0.,]
 [ 0., 0., 0., 0., 0., 0., 0., 0., 0., 0.,]
 [ 0., 0., 0., 0., 0., 0., 0., 0., 0., 0.,]
 [ 0., 0., 0., 0., 0., 0., 0., 0., 0., 0.,]
 [ 0., 0., 0., 0., 0., 0., 0., 0., 0., 0.,]
 [ 0., 0., 0., 0., 0., 0., 0., 0., 0., 0.,]
 [ 0., 0., 0., 0., 0., 0., 0., 0., 0., 0.,]
 [ 0., 0., 0., 0., 0., 0., 0., 0., 0., 0.,]
 [ 0., 0., 0., 0., 0., 0., 0., 0., 0., 0.,]
 [ 0., 0., 0., 0., 0., 0., 0., 0., 0., 0.,]]
        s1 = 0.78583498304255861
    778             matrix[1,0] = s2
    779             matrix[2,1] = s3

ValueError: cannot handle misaligned or not writeable arrays.


--
Chris Fonnesbeck
Atlanta, GA



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