On Wed, Feb 10, 2010 at 11:24 AM, Gökhan Sever <gokhanse...@gmail.com> wrote: > > > On Wed, Feb 10, 2010 at 10:12 AM, Gökhan Sever <gokhanse...@gmail.com> > wrote: >> >> >> On Wed, Feb 10, 2010 at 10:06 AM, Angus McMorland <amcm...@gmail.com> >> wrote: >>> >>> On 10 February 2010 11:02, Gökhan Sever <gokhanse...@gmail.com> wrote: >>> > Hi, >>> > >>> > Simple question: >>> > >>> > I[4]: a = np.arange(10) >>> > >>> > I[5]: b = np.array(5) >>> > >>> > I[8]: a*b.cumsum() >>> > O[8]: array([ 0, 5, 10, 15, 20, 25, 30, 35, 40, 45]) >>> > >>> > I[9]: np.array(a*b).cumsum() >>> > O[9]: array([ 0, 5, 15, 30, 50, 75, 105, 140, 180, 225]) >>> > >>> > Is there a syntactic equivalent for the I[9] --for instance instead of >>> > using >>> > "list" keyword I use [ ] while creating a list. Is there a shortcut for >>> > np.array instead of writing np.array(a*b) explicitly? >>> >>> How about just (a*b).cumsum() ? >>> >>> Angus. >>> -- >>> AJC McMorland >>> Post-doctoral research fellow >>> Neurobiology, University of Pittsburgh >>> _______________________________________________ >>> NumPy-Discussion mailing list >>> NumPy-Discussion@scipy.org >>> http://mail.scipy.org/mailman/listinfo/numpy-discussion >> >> Yep that's it :) I knew that it was a very simple question. >> >> What confused me is I remember somewhere not sure maybe in IPython dev I >> have gotten when I do: >> >> (a*b).cumsum() >> >> AttributeError: 'tuple' object has no attribute 'cumsum' error. >> >> So I was thinking ( ) is a ssugar for tuple and np.array might have >> something special than these. >> >> -- >> Gökhan > > Self-correction: > > It works correctly in IPython-dev as well. > > And further in Python 2.6.2: > >>>> p = () >>>> p > () >>>> type(p) > <type 'tuple'> >>>> type((a*b)) > <type 'numpy.ndarray'> > > ( ) doesn't only works as a tuple operator. It also has its original > parenthesis functionality :)
except for empty tuple constructor, a comma defines a tuple and parenthesis are just parenthesis >>> type((a*b)) <type 'numpy.ndarray'> >>> type((a*b,)) <type 'tuple'> >>> a*b, (array([0, 1]),) >>> type(_) <type 'tuple'> Josef > > -- > Gökhan > > _______________________________________________ > 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
