"aeneng" <aeneng at yahoo.com> wrote in message news:fsk739+ff60 at eGroups.com... | def cross(u,v) | """input two vectors u and v in 3-D space, | output a cross product of vector w, in column or in row | accordingly.""" | ppp1,ppp2,ppp3=0.0,0.0,0.0 To add to other comments, remove above which is complete waste.