Thank you both! Broadcasting is a concept I hadn't yet read about, but knew was important for efficient python programming... thanks for the link!
On Sat, Nov 27, 2010 at 6:44 PM, Eike Welk <eike.w...@gmx.net> wrote: > Hello John! > > On Friday 26.11.2010 23:23:51 Peter Otten wrote: >> John wrote: >> > I know this is a simple problem, but I want to do it the most >> > efficient way (that is vectorized...) >> > >> > import numpy as np >> > >> > a = np.array(([1,2,3,4],[1,.2,3,4],[1,22,3,4])) >> > b = np.sum(a,axis=1) >> > >> > for i,elem in enumerate(a): >> > a[i,:] = elem/b[i] >> > >> > suggestions? >> >> I'm not a numpy expert, but: >> >> (a.transpose()/np.sum(a, axis=1)).transpose() > > The underlying feature of Peter's solution is called broadcasting. For a > detailed explanation look at: > http://docs.scipy.org/doc/numpy/user/basics.broadcasting.html > > > Eike. > _______________________________________________ > Tutor maillist - tu...@python.org > To unsubscribe or change subscription options: > http://mail.python.org/mailman/listinfo/tutor > -- Configuration `````````````````````````` Plone 2.5.3-final, CMF-1.6.4, Zope (Zope 2.9.7-final, python 2.4.4, linux2), Python 2.6 PIL 1.1.6 Mailman 2.1.9 Postfix 2.4.5 Procmail v3.22 2001/09/10 Basemap: 1.0 Matplotlib: 1.0.0 _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
