On Tue, Aug 25, 2009 at 16:18, Giuseppe Aprea<giuseppe.ap...@gmail.com> wrote: > Hi, I would like to do something like this > > a=array([[1,2,3,4],[5,6,7,8],[4,5,6,0]]) > idxList=[] > for i in range(0,a.shape[1]): > if len(nonzero(a[:,i])[0])==1: #want to extract column indices > of those columns which only have one non vanishing element > idxList.append(i) > > I already used where on !D array but I don't know if there is some function or > some kind of syntax which allow you to evaluate a condition for each > column(row).
column_mask = ((a != 0).sum(axis=1) == 1) idxArray = np.nonzero(column_mask)[0] # if you must -- 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 NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
