2018-08-21 08:40:34 -0500 received badge ● Popular Question (source) 2015-03-06 20:31:09 -0500 received badge ● Scholar (source) 2015-03-06 18:16:44 -0500 received badge ● Student (source) 2015-03-06 15:45:30 -0500 asked a question plot surface plus vector field My apologies for posting a (hopefully) simple question. I want to plot a surface with the gradient field in the plane underneath. I can create the surface and vector field separately, but I get an error when I try to show them on the same axes. It seems that the vector field is a different type. Does anyone know how to induce the vector field so it can be plotted as part of a 3d plot? I'd like to do something like this: f(x,y)=y/(1-x+y) P=plot3d(f(x,y),(x,0,1),(y,0,1)) gradf=vector([y/(x-y-1)^2,(1-x)/(x-y-1)^2]) VF=plot_vector_field(gradf,(x,0,1),(y,0,1)) show(P+VF)  Everything but that last step works great, and then I get an error message: NotImplementedError: 3D plotting not implemented for PlotField defined by a 20 x 20 vector grid  Can anyone suggest a workaround? Thanks for your help!