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Re: Export Plot3D as text

  • To: mathgroup at
  • Subject: [mg112937] Re: Export Plot3D as text
  • From: Fred Klingener <gigabitbucket at>
  • Date: Wed, 6 Oct 2010 03:17:37 -0400 (EDT)
  • References: <i8c8r0$g68$>

On Oct 4, 6:04 am, Laura Elizabeth McMullen
<mcmul... at> wrote:
> Hi all-
> I have functions I am plotting in 3D in Mathematica, defining ranges  
> of values for two of the variables in the function with the Plot3D  
> command.  I would like to reproduce these plots in another program,  
> but am having difficulty exporting the data in a useful format.  I  
> would like the data to be lists of numerical data, but when I export  
> the data as text, the file is huge.  Any suggestions?  Thanks for your  
> help.

There are probably very terse and elegant ways to get this, but I
usually have to start with brute force. Here's a Plot3D from the doc

p = Plot3D[Sin[x + y^2], {x, -3, 3}, {y, -2, 2}]

This shows the structure, a GraphicsComplex inside a Graphics3D:

p // FullForm

You can look at the basic structure with

{Head[#], Length[#], Depth[#]} &@p

{Graphics3D, 2, 11}

p[[1]] is the GraphicsComplex and p[[2]] is the Option list for the

Looking at the GC:

In[19]:= {Head[#], Length[#], Depth[#]} & /@ p[[1, 1 ;; 3]]

Out[19]= GraphicsComplex[{List, 3372, 3}, {List, 2, 9}, {Rule, 2, 4}]

So the simplest useful thing you probably want to export is the
surface node list p[[1, 1]], but connectivity and vertex normals are
in 2;;3 if you need refinement.

p[[1, 1]] can be 'huge,' but as a List, it's a lot easier to handle
than a text file.

Fred Klingener

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