Numpy/Scipy set field of matrix?

[cnb]

, 'argmax', 'argmin', 'argsort', 'astype', 'base', 'byteswap',
'choose', 'clip', 'compress', 'conj', 'conjugate', 'copy', 'ctypes',
'cumprod', 'cumsum', 'data', 'diagonal', 'dtype', 'dump', 'dumps',
'fill', 'flags', 'flat', 'flatten', 'getA', 'getA1', 'getH', 'getI',
'getT', 'getfield', 'imag', 'item', 'itemset', 'itemsize', 'max',
'mean', 'min', 'nbytes', 'ndim', 'newbyteorder', 'nonzero', 'prod',
'ptp', 'put', 'ravel', 'real', 'repeat', 'reshape', 'resize', 'round',
'searchsorted', 'setfield', 'setflags', 'shape', 'size', 'sort',
'squeeze', 'std', 'strides', 'sum', 'swapaxes', 'take', 'tofile',
'tolist', 'tostring', 'trace', 'transpose', 'var', 'view']

>>> m
matrix([[1, 2, 3],
        [4, 5, 6],
        [7, 8, 9]])

how do I set the field 1,2 (=6) to 45 for example?


and how do I initialize a matrix and then add values in a for-loop?

Im using PIL and want to store all the pixels of an image in a matrix.

But I can't find the appropriate operations.