On Mar 22, 2007, at 8:13 PM, Brian Blais wrote: > Hello, > > I'd like to concatenate a couple of 1D arrays to make it a 2D > array, with two columns > (one for each of the original 1D arrays). I thought this would work: > > > In [47]:a=arange(0,10,1) > > In [48]:a > Out[48]:array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]) > > In [49]:b=arange(-10,0,1) > > In [51]:b > Out[51]:array([-10, -9, -8, -7, -6, -5, -4, -3, -2, -1]) > > In [54]:concatenate((a,b)) > Out[54]: > array([ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -10, -9, > -8, > -7, -6, -5, -4, -3, -2, -1]) > > In [55]:concatenate((a,b),axis=1) > Out[55]: > array([ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -10, -9, > -8, > -7, -6, -5, -4, -3, -2, -1]) > > > but it never expands the dimensions. Do I have to do this... > > In [65]:concatenate((a.reshape(10,1),b.reshape(10,1)),axis=1) > Out[65]: > array([[ 0, -10], > [ 1, -9], > [ 2, -8], > [ 3, -7], > [ 4, -6], > [ 5, -5], > [ 6, -4], > [ 7, -3], > [ 8, -2], > [ 9, -1]]) > > > ? > > I thought there would be an easier way. Did I overlook something?
What's wrong with zip? Or did *I* miss the point? (I'm just getting the hang of numpy.) ~ $ python Python 2.5 (r25:51918, Sep 19 2006, 08:49:13) [GCC 4.0.1 (Apple Computer, Inc. build 5341)] on darwin Type "help", "copyright", "credits" or "license" for more information. >>> from numpy import * >>> a=arange(0,10,1) >>> a array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]) >>> b=arange(-10,0,1) >>> b array([-10, -9, -8, -7, -6, -5, -4, -3, -2, -1]) >>> array(zip(a,b)) array([[ 0, -10], [ 1, -9], [ 2, -8], [ 3, -7], [ 4, -6], [ 5, -5], [ 6, -4], [ 7, -3], [ 8, -2], [ 9, -1]]) >>> Bob Pyle _______________________________________________ Numpy-discussion mailing list Numpy-discussion@scipy.org http://projects.scipy.org/mailman/listinfo/numpy-discussion