On 8/03/13 8:37 AM, Damon McDougall wrote: > Correct me if I'm wrong, but would a 2D quiver plot on top of a > contour plot work? What spaces does the surface map to/from? If your > surface can be expressed as a function f:R^2 -> R then it's equivalent > to look at its level sets, rather than the 3D picture. You can then > project the surface normals onto the plane and plot them with a 2D > quiver plot. If you want to keep the z-component information, then > you could colour the arrows according to the angle they make with the > x-y plane. > > Does that make sense?
My source is an image, so technically f:R^2 -> R. Specifically I am using depth maps or (range image) what to visualise the surfaces/normals. I was planing on plotting the image as surface (hadn't work out how yet) and overlay the normal vectors. I think a 2D quiver plot on top of a contour plot may provide a useful visualisation/interpretation of the process. Thanks for the idea. Brickle. -- > > I put the original feature request in, and I think it would be useful, > but often I still find it easier to process two dimensional > information. > > N.B. The above will only work for *functions* f:R^2 -> R. To > clarify, a sphere cannot be expressed this way, because the resulting > mapping would be multivalued. Using this method, two distinct surface > normals may have the same colour. > > Hope that makes sense. > > Best wishes, > Damon > >> Brickle. >> -- >> >> >> On 8/03/13 5:43 AM, Benjamin Root wrote: >> >> >> >> On Thu, Mar 7, 2013 at 4:25 PM, Eric Firing <efir...@hawaii.edu> wrote: >>> On 2013/03/07 9:19 AM, Benjamin Root wrote: >>>> >>>> On Thu, Mar 7, 2013 at 2:14 PM, Brickle Macho <bricklema...@gmail.com >>>> <mailto:bricklema...@gmail.com>> wrote: >>>> >>>> I have a list of surface normals I would like to plot. Is there a >>>> way >>>> to plot a 3D vectors in matplotlib similar to how quiver plots 2D >>>> vectors? >>>> >>>> >>>> Not at this time, but that would make a great feature request! I think >>>> the current roadblock to such a function is a bug with converting 2d >>>> arrow objects into 3d arrows. >>> Quiver uses a PolyCollection, and I see that there is a Poly3DCollection. >>> >>> Eric >>> >>>> Ben Root >>> >> Took a bit of digging, but I knew I remembered this question before: >> >> http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&ved=0CDMQFjAA&url=http%3A%2F%2Fmatplotlib.1069221.n5.nabble.com%2F2D-Quiver-in-Axes3D-td27944.html&ei=Pwk5UfGdLufv0QHuroD4BA&usg=AFQjCNEqlWv2vY5l2IPcje-g6B0U21wDNw&bvm=bv.43287494,d.dmQ >> >> And the feature request is here: >> https://github.com/matplotlib/matplotlib/issues/1026 >> >> In the thread I pointed out a bug that I encountered. I really hope I get >> some free time soon so that I can work on the various feature requests in >> mplot3d. >> >> Cheers! >> Ben Root >> >> >> >> ------------------------------------------------------------------------------ >> Symantec Endpoint Protection 12 positioned as A LEADER in The Forrester >> Wave(TM): Endpoint Security, Q1 2013 and "remains a good choice" in the >> endpoint security space. For insight on selecting the right partner to >> tackle endpoint security challenges, access the full report. >> http://p.sf.net/sfu/symantec-dev2dev >> >> >> >> _______________________________________________ >> Matplotlib-users mailing list >> Matplotlib-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/matplotlib-users >> >> >> >> ------------------------------------------------------------------------------ >> Symantec Endpoint Protection 12 positioned as A LEADER in The Forrester >> Wave(TM): Endpoint Security, Q1 2013 and "remains a good choice" in the >> endpoint security space. For insight on selecting the right partner to >> tackle endpoint security challenges, access the full report. >> http://p.sf.net/sfu/symantec-dev2dev >> _______________________________________________ >> Matplotlib-users mailing list >> Matplotlib-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/matplotlib-users >> > > ------------------------------------------------------------------------------ Symantec Endpoint Protection 12 positioned as A LEADER in The Forrester Wave(TM): Endpoint Security, Q1 2013 and "remains a good choice" in the endpoint security space. For insight on selecting the right partner to tackle endpoint security challenges, access the full report. http://p.sf.net/sfu/symantec-dev2dev _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
