Hi, On Mon, Jun 17, 2013 at 12:07 PM, Bala subramanian <bala.biophys...@gmail.com> wrote: > Friends, > I have to save only the lower half of a symmetric matrix to a file. I used > numpy.tril to extract the lower half. However when i use 'numpy.savetxt', > numpy saves the whole matrix (with upper half values replaced as zeros) > rather than only the lower half. Any better idea to achieve this. > > as an example >>>>import numpy as np >>>> d=np.arange(1,26,1) >>>> d=d.reshape(5,5) >>>> np.tril(d) > array([[ 1, 0, 0, 0, 0], > [ 6, 7, 0, 0, 0], > [11, 12, 13, 0, 0], > [16, 17, 18, 19, 0], > [21, 22, 23, 24, 25]]) > >>>> np.savetxt( 'test', np.tril(d)) > output test also contains the zeros, what i want is only the lower half like > below. > 1 > 6 7 > 11 12 13 > - - - - etc
Maybe you want something like: e = d[np.tril_indices(5)] ? Best, Matthew _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
