On 3/22/07, Stefan van der Walt <[EMAIL PROTECTED]> wrote: > On Thu, Mar 22, 2007 at 08:13:22PM -0400, 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? > > How about > > N.vstack((a,b)).T > Also mentioned here should be the use of newaxis. As in a[:,newaxis]
However I never got a "good feel" for how to use it, so I can't complete the code you would need. -Sebastian Haase _______________________________________________ Numpy-discussion mailing list Numpy-discussion@scipy.org http://projects.scipy.org/mailman/listinfo/numpy-discussion
