Skip to main content

Export ContourPlot as DXF


I'm having some trouble exporting a ContourPlot as a .DXF (to be used in AutoCAD).


My code is:


LG3 = ContourPlot[1/2 - Sum[Sinc[(n \[Pi])/2] Cos[n (1 x + 4 ArcTan[y, x])], {n, 1, 200}] == 0.5,
  {x, -20, 20},
  {y, -20, 20},
  PlotPoints -> 100]
SetDirectory[NotebookDirectory[]];

Export["LG3.dxf", LG3];

The relevant output is:



Export::nodta: Graphics3D contains no data that can be exported to the DXF format. >>



Any help would be appreciated. Thanks.



Answer



DXF export is somewhat idiosyncratic (3D only) and slow. For the following I´ve reduced PlotPoints to make casual experimenting less glacial. The general idea is to extract all Line primitives and elevate coordinate tuples to 3D.


LG3 = ContourPlot[

   1/2 - Sum[Sinc[(n π)/2] Cos[n (1 x + 4 ArcTan[y, x])], {n, 1, 200}] ==
     0.5, {x, -20, 20}, {y, -20, 20}, PlotPoints -> 20];

threed = Graphics3D[Cases[Normal[LG3[[1]]], _Line, Infinity] /. {x_?NumericQ, y_?NumericQ} :> {x, y, 0}]
Export["LG3.dxf", threed]

Mathematica graphics


Whether this will agree with your further processing is another question, in Rhino3D this works well enough.


Mathematica graphics


If you want 2D bells and whistles, you would have to roll your own DXF export (doable, but not necessarily pretty).



Addendum (a.k.a not pretty):


This is some really old (and quite probably astonishingly bad/embarassing code) that I have been using with good success for years and have not updated since its first working incarnation except for version caveats (talk about cruft). Use at your own risk. Please feel free to update to a sleek new design.


It takes a very limited set of 2D primitives (Line, Circle and Point) and returns a 2D DXF. One useful thing it does is to build blocks out of top-level list objects, which can be really useful when editing large groups of lines etc. For your example the export is much zippier than the inbuilt one.


ToN[number_, digits_: 8] := 
 PaddedForm[number // N, {20, digits}, NumberPadding -> {"", "0"}, 
  ExponentFunction -> (Null &)]

ToDXF[gobject_] := 
 Module[{header1, layers, startblocks, endblocks, startentities, 
   endentities, footer, rPOLYLINE, rARC, rCIRCLE, rPOINT, rBLOCK, g0, 

   blockobjects, insertobjects, rINSERT, entities, gexport, allowed},
  header1 = {"  999", 
    "Ugly DXF export from Mathematica by Yves Klett", "  0", "SECTION", "  2", "HEADER", "  9", "$ACADVER", 
    "  1", "AC1009",  "0", "ENDSEC"};
  layers = {"  0", "SECTION", "  2", "TABLES", "  0", "TABLE", "  2", 
    "LAYER", "  70", "1", "  0", "LAYER", "  2", "0", "  70", "64", 
    "  62", "8", "  0", "ENDTAB", "  0", "ENDSEC"};
  startblocks = {"  0", "SECTION", "  2", "BLOCKS"};
  endblocks = {"  8", "0", "  0", "ENDSEC"};
  startentities = {"  0", "SECTION", "  2", "ENTITIES"};

  endentities = {"  0", "ENDSEC"};
  footer = {"  0", "EOF", ""};
  rPOLYLINE = 
   Line[pts_] :> 
    ToString /@ 
     Flatten[{"  0", "POLYLINE", "  8", "0", " 66", "1", " 70", "0", 
       "  0", {"VERTEX", "  8", "0", "  10", ToN[#[[1]]] // ToString, 
          "  20", ToN[#[[2]]] // ToString, "  0"} & /@ pts, "SEQEND", 
       "  8", "0"}];
  rARC = Circle[m_, r_, {ϕ1_, ϕ2_}] :> {"  0", "ARC", "  8",

      "0", "  10", ToN[m[[1]]] // ToString, "  20", 
     ToN[m[[2]]] // ToString, "  30", "0", "  40", ToN[r] // ToString,
      "  50", ToN[ϕ1*180/π] // ToString, "51  ", 
     ToN[ϕ2*180/π] // ToString};
  rCIRCLE = 
   Circle[m_, r_] :> {"  0", "CIRCLE", "  8", "0", "  10", 
     ToN[m[[1]]] // ToString, "  20", ToN[m[[2]]] // ToString, "  30",
      "0", "  40", ToN[r] // ToString};
  rPOINT = 
   Point[{x_, y_}] :> {"  0", "POINT", "  8", "0", "  10", 

     ToN[x] // ToString, "  20", ToN[y] // ToString, "  30", "0"};
  rBLOCK = 
   objs_ :> {MapIndexed[{"  0", "BLOCK", "  2", 
        "obj" <> ToString[#2[[1]]], #1, "  0", "ENDBLK"} &, objs]};
  allowed = (Line[__] | Circle[__] | Point[__] | List[__]);
  g0 = Flatten /@ 
    If[Head[gobject] == Graphics, gobject[[1]], gobject, gobject];
  blockobjects = (DeleteCases[g0, Except[allowed], 2] /. rPOLYLINE /. 
        rARC /. rCIRCLE /. rPOINT) /. rBLOCK;
  insertobjects = 

   Select[ToString /@ (blockobjects // Flatten), 
    StringMatchQ[#1, "obj" ~~ ___] &];
  rINSERT = 
   objs_ :> 
    Map[{"  0", "INSERT", "  2", #, "  8", "0", "  10", "0", "  20", 
       "0"} &, objs];
  entities = insertobjects /. rINSERT;
  gexport = {header1, layers, startblocks, blockobjects, endblocks, 
     startentities, entities, endentities, footer} // Flatten;
  gexport

  ]

ExportToDXF[filename_, gobject_] := If[$VersionNumber < 6,
  Export[filename, ToDXF[gobject] // ColumnForm, "Text"],
  Export[filename, Riffle[ToDXF[gobject], "\n"] // StringJoin, "Text"]
  ]

Block usage (colors are not exported):


block1 = {Red, Circle[{0, 0}, 5], 
   Line[{{-5, -5}, {5, 5}, {-5, 5}, {5, -5}, {-5, -5}}]};

block2 = {Blue, Circle[{5, 0}, 5, {0, π}], Line[{{0, 0}, {5, 0}}],
    Point[{-2, 0}]};

g = {block1, block2};

Graphics[g]
ExportToDXF["tst.dxf", g];

Mathematica graphics


This Rhino screenshot shows the grouping of the primitives: Mathematica graphics



Comments

Post a Comment

Popular posts from this blog

plotting - Filling between two spheres in SphericalPlot3D

Manipulate[ SphericalPlot3D[{1, 2 - n}, {θ, 0, Pi}, {ϕ, 0, 1.5 Pi}, Mesh -> None, PlotPoints -> 15, PlotRange -> {-2.2, 2.2}], {n, 0, 1}] I cant' seem to be able to make a filling between two spheres. I've already tried the obvious Filling -> {1 -> {2}} but Mathematica doesn't seem to like that option. Is there any easy way around this or ... Answer There is no built-in filling in SphericalPlot3D . One option is to use ParametricPlot3D to draw the surfaces between the two shells: Manipulate[ Show[SphericalPlot3D[{1, 2 - n}, {θ, 0, Pi}, {ϕ, 0, 1.5 Pi}, PlotPoints -> 15, PlotRange -> {-2.2, 2.2}], ParametricPlot3D[{ r {Sin[t] Cos[1.5 Pi], Sin[t] Sin[1.5 Pi], Cos[t]}, r {Sin[t] Cos[0 Pi], Sin[t] Sin[0 Pi], Cos[t]}}, {r, 1, 2 - n}, {t, 0, Pi}, PlotStyle -> Yellow, Mesh -> {2, 15}]], {n, 0, 1}]
Post a Comment
Read more

plotting - Plot 4D data with color as 4th dimension

I have a list of 4D data (x position, y position, amplitude, wavelength). I want to plot x, y, and amplitude on a 3D plot and have the color of the points correspond to the wavelength. I have seen many examples using functions to define color but my wavelength cannot be expressed by an analytic function. Is there a simple way to do this? Answer Here a another possible way to visualize 4D data: data = Flatten[Table[{x, y, x^2 + y^2, Sin[x - y]}, {x, -Pi, Pi,Pi/10}, {y,-Pi,Pi, Pi/10}], 1]; You can use the function Point along with VertexColors . Now the points are places using the first three elements and the color is determined by the fourth. In this case I used Hue, but you can use whatever you prefer. Graphics3D[ Point[data[[All, 1 ;; 3]], VertexColors -> Hue /@ data[[All, 4]]], Axes -> True, BoxRatios -> {1, 1, 1/GoldenRatio}]
Post a Comment
Read more

plotting - Mathematica: 3D plot based on combined 2D graphs

I have several sigmoidal fits to 3 different datasets, with mean fit predictions plus the 95% confidence limits (not symmetrical around the mean) and the actual data. I would now like to show these different 2D plots projected in 3D as in but then using proper perspective. In the link here they give some solutions to combine the plots using isometric perspective, but I would like to use proper 3 point perspective. Any thoughts? Also any way to show the mean points per time point for each series plus or minus the standard error on the mean would be cool too, either using points+vertical bars, or using spheres plus tubes. Below are some test data and the fit function I am using. Note that I am working on a logit(proportion) scale and that the final vertical scale is Log10(percentage). (* some test data *) data = Table[Null, {i, 4}]; data[[1]] = {{1, -5.8}, {2, -5.4}, {3, -0.8}, {4, -0.2}, {5, 4.6}, {1, -6.4}, {2, -5.6}, {3, -0.7}, {4, 0.04}, {5, 1.0}, {1, -6.8}, {2, -4.7}, {3, -1.
Post a Comment
Read more