Robin wrote: > Hi, > > I have a problem using numpy.dot, see below: > > In [151]: m=5 > > In [152]: n=5 > > In [153]: x=(m*ones((1,5)))**arange(0,n) > > In [154]: y=test.order_length[::-1] > > In [155]: x > Out[155]: array([[ 1., 5., 25., 125., 625.]]) > > In [156]: y > Out[156]: > array([[ 1024.], > [ 1280.], > [ 640.], > [ 160.], > [ 20.]]) > > In [157]: numpy.dot(x,y) > Out[157]: array([[ 640000.]]) > > In [158]: sum(x* y.T) > Out[158]: 55924.0 > > Am I missing something?
In [1]: from numpy import * In [2]: x = array([[ 1., 5., 25., 125., 625.]]) In [3]: y = array([[ 1024.], ...: [ 1280.], ...: [ 640.], ...: [ 160.], ...: [ 20.]]) In [4]: dot(x, y) Out[4]: array([[ 55924.]]) In [5]: sum(x * y.T) Out[5]: 55924.0 It works for me with a recent SVN numpy on OS X. What version of numpy are you using? What platform are you on? Did you build with ATLAS or other optimized linear algebra library? -- Robert Kern "I have come to believe that the whole world is an enigma, a harmless enigma that is made terrible by our own mad attempt to interpret it as though it had an underlying truth." -- Umberto Eco _______________________________________________ Numpy-discussion mailing list [email protected] http://projects.scipy.org/mailman/listinfo/numpy-discussion
