On Wed, Mar 30, 2011 at 1:42 PM, gary ruben <gru...@bigpond.net.au> wrote: > You're right, they are not equivalent. vstack will happily create an > array of higher rank than the parts it is stacking, whereas > concatenate requires the arrays it is working with to already be at > least 2d, so the equivalent is > np.concatenate((np.arange(5.)[newaxis],np.arange(5.)[newaxis]), axis=0) > or > np.concatenate((np.atleast_2d(np.arange(5.)),np.atleast_2d(np.arange(5.))), > axis=0)
This is fixed in the docstring now. Ralf > On Wed, Mar 30, 2011 at 9:30 PM, andrew nelson <andyf...@gmail.com> wrote: >> Dear List, >> I have a quick question regarding vstack and concatenate. >> In the docs for vstack it says that: >> >> np.concatenate(tup, axis=0) >> >> should be equivalent to: >> >> np.vstack(tup) >> >> However, I tried this out and it doesn't seem to be case, i.e. >> >>>>> np.vstack((np.arange(5.), np.arange(5.))) >> array([[ 0., 1., 2., 3., 4.], >> [ 0., 1., 2., 3., 4.]]) >> >>>>> np.concatenate((np.arange(5.),np.arange(5.)), axis=0) >> array([ 0., 1., 2., 3., 4., 0., 1., 2., 3., 4.]) >> >> These aren't the same. Maybe I'm missing something? >> >> regards, >> Andrew. >> _______________________________________________ >> NumPy-Discussion mailing list >> NumPy-Discussion@scipy.org >> http://mail.scipy.org/mailman/listinfo/numpy-discussion >> > _______________________________________________ > NumPy-Discussion mailing list > NumPy-Discussion@scipy.org > http://mail.scipy.org/mailman/listinfo/numpy-discussion > _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
