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plotting - Converting Mesh in DensityPlot to a Graph



Consider the following line of code:


DensityPlot[4 Sin[2 Pi x] Cos[1.5 Pi y] (1 - x^2) (1 - y) y, 
{x, -1, 1}, {y, 0, 1}, Mesh -> All, MeshStyle -> Thick]

with the following output:


mesh


How can I convert the shown mesh into a Graph object such that:




  1. All the vertices are aligned at the intersection of the lines, with correct VertexCoordinates.





  2. The edges (line segments in the plot) connect the corresponding vertices.




Note: If g is the resulting Graph, then the following code should give the same figure as the one above:


Show[DensityPlot[4 Sin[2 Pi x] Cos[1.5 Pi y] (1 - x^2) (1 - y) y, {x, -1, 1}, {y, 0, 1}], g]

Answer



This will do


densPlot = 

DensityPlot[
4 Sin[2 Pi x] Cos[1.5 Pi y] (1 - x^2) (1 - y) y, {x, -1, 1}, {y, 0,
1}, MeshStyle -> Thick, Mesh -> All];

vertexCoordinates = densPlot[[1, 1]];

length = Length[vertexCoordinates];

graphReadyConnections =
DeleteDuplicates@

Flatten[
Cases[#,
List[x_, y_, z_] :> {Sort[x \[UndirectedEdge] y],
Sort[x \[UndirectedEdge] z], Sort[y \[UndirectedEdge] z]},
Infinity] &@
densPlot[[1, 2, 1, 1, 3, 1, 1, 1]]
,
1
];


Graph[Range[length], graphReadyConnections,
VertexCoordinates -> vertexCoordinates,
VertexShapeFunction -> {Disk[#, 0.005] &}, ImageSize -> 800]

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