Le vendredi 04 avril 2008 à 00:28 -0700, wilson a écrit : > > #of shape (1,6) > > eval=array([[3.,3.2,1.,1.1,5.,0.5]]) > > > > eval.shape=(-1,) > > please not the correction..i need to multiply first row of egimgs with > 3.0 ,second row with 3.2,....last(sixth) row with 0.5 ..For that > purpose i made the above into a 1 dimensional array. > A for loop seems inefficient in the case of big arrays > W
Hi I suggest you three ways: * using matrices : mat(eval*identity(eval.shape[1]))*mat(egimgs) creates first a diagonal matrix with eval coefficients on main diagonal, then multiply the matrices diagonal and egimgs * using a temporary matrix with repeated eval coefficients eval.T.repeat(egimgs.shape[1],axis=1)*egimgs repeats array eval as many times as required to have two arrays of the same size that can be multiplied. and maybe the more efficient that does not require you to create a temp array of size egimgs.shape : eval.T*egimgs or for inplace update of egimgs egimgs *= eval.T provided the len of 1darray and one of the dimension of the 2darray match, you can multiply them directly. -- Fabrice Silva, PhD student LMA UPR CNRS 7051 - équipe S2M _______________________________________________ Numpy-discussion mailing list Numpy-discussion@scipy.org http://projects.scipy.org/mailman/listinfo/numpy-discussion