On Apr 11, 4:18�pm, George Sakkis <george.sak...@gmail.com> wrote: > On Apr 11, 4:14�pm, ergconce...@googlemail.com wrote: > > > > > > > Hi, > > I have a list looking like > > > [ 0.84971586, �0.05786009, �0.9645675, �0.84971586, �0.05786009, > > 0.9645675, 0.84971586, �0.05786009, �0.9645675, �0.84971586, > > 0.05786009, �0.9645675] > > > and I would like to break this list into subsets of fixed length (say, > > three elements), i.e. to convert the list into a form such as the one > > generated by the following example code which I have found: > > > >>>import numpy > > >>>s = numpy.random.random((3,3)) > > >>>s > > > array([[ 0.11916176, �0.96409475, �0.72602155], > > � � � �[ 0.84971586, �0.05786009, �0.96456754], > > � � � �[ 0.81617437, �0.845342 �, �0.09109779]]) > > > How can I create such a 2d array (i.e., something like a symmetric > > matrix) from my data? > > > Thanks in advance, > > > Bernard > > > PS: Note that the numpy import is not important here, it is just the > > structure of the data that matters.. > > The numpy import *is* important if you want to use numpy-specific > features; there are many "tricks" you can do easily with numpy arrays > that you have to write manually for, say, regular python lists. For > example what you want to do is trivial with numpy: > > >>>import numpy as N > >>> s = N.array([ 0.84971586, �0.05786009, �0.9645675, �0.84971586, > >>> �0.05786009, > > 0.9645675, 0.84971586, �0.05786009, �0.9645675, �0.84971586, > 0.05786009, �0.9645675])>>> # convert to a 4by3 array in place > >>> s.shape = (4,3) > >>> s
What does numpy do if the original list has 13 elements? > > array([[ 0.84971586, �0.05786009, �0.9645675 ], > � � � �[ 0.84971586, �0.05786009, �0.9645675 ], > � � � �[ 0.84971586, �0.05786009, �0.9645675 ], > � � � �[ 0.84971586, �0.05786009, �0.9645675 ]]) > > HTH, > George -- http://mail.python.org/mailman/listinfo/python-list
