improve Eikmesh to handle extreme slim obstacles.

VadereMeshing/resources/poly/railing.poly

+# nVertices dimension nAttributes boundaryMarker
+20 2 0 0
+# vertexId x y
+1 0.500000 0.500000
+2 61.903197 8.064521
+3 38.841269 14.606642
+4 40.029782 19.726267
+5 0.500000 99.500000
+6 44.390559 12.250599
+7 43.789522 11.865840
+8 45.212895 18.026666
+9 40.404106 19.127630
+10 31.586493 15.912108
+11 31.682452 90.622759
+12 39.213217 13.997772
+13 38.261243 89.048447
+14 62.005890 8.553862
+15 31.179013 91.257350
+16 99.500000 0.500000
+17 45.813087 18.402190
+18 32.084388 16.302644
+19 99.500000 99.500000
+20 38.377608 89.534717
+#
+# nSegments boundaryMarker
+20 0
+# lineId vertexId1 vertexId2
+1 16 19
+2 19 5
+3 5 1
+4 1 16
+5 3 4
+6 4 17
+7 17 6
+8 6 14
+9 14 2
+10 2 7
+11 7 8
+12 8 9
+13 9 12
+14 12 10
+15 10 15
+16 15 20
+17 20 13
+18 13 11
+19 11 18
+20 18 3
+#
+# nHoles
+1
+# vertexId x y (of a vertex which lies inside the hole)
+1 31.184013 90.334521
\ No newline at end of file

VadereMeshing/src/org/vadere/meshing/examples/BackgroundMeshExamples.java

@@ -4,6 +4,7 @@ import org.jetbrains.annotations.NotNull;
 import org.vadere.meshing.mesh.gen.MeshPanel;
 import org.vadere.meshing.mesh.impl.PMeshPanel;
 import org.vadere.meshing.mesh.impl.PSLG;
+import org.vadere.meshing.mesh.triangulation.DistanceFunctionApproxBF;
 import org.vadere.meshing.mesh.triangulation.EdgeLengthFunctionApprox;
 import org.vadere.meshing.mesh.triangulation.improver.eikmesh.impl.PEikMesh;
 import org.vadere.meshing.mesh.triangulation.triangulator.gen.GenRuppertsTriangulator;
@@ -11,6 +12,7 @@ import org.vadere.meshing.mesh.triangulation.triangulator.impl.PContrainedDelaun
 import org.vadere.meshing.mesh.triangulation.triangulator.impl.PDelaunayTriangulator;
 import org.vadere.meshing.mesh.triangulation.triangulator.impl.PRuppertsTriangulator;
 import org.vadere.meshing.utils.io.poly.PSLGGenerator;
+import org.vadere.util.math.IDistanceFunction;
 
 import java.io.IOException;
 import java.io.InputStream;
@@ -25,12 +27,23 @@ public class BackgroundMeshExamples {
 		//localFeatureSize("/poly/narrowCorridor.poly");
 		//localFeatureSize("/poly/bridge.poly");
 		localFeatureSize("/poly/mf_small_very_simple.poly");
+		//distance("/poly/mf_small_very_simple.poly");
+		//distance("/poly/mf_small_very_simple.poly");
 	}
 
 	public static void localFeatureSize(@NotNull final String fileName) throws IOException {
 		final InputStream inputStream = MeshExamples.class.getResourceAsStream(fileName);
 		PSLG pslg = PSLGGenerator.toPSLGtoVShapes(inputStream);
 		EdgeLengthFunctionApprox edgeLengthFunctionApprox = new EdgeLengthFunctionApprox(pslg);
+		//edgeLengthFunctionApprox.smooth(0.2);
 		edgeLengthFunctionApprox.printPython();
 	}
+
+	public static void distance(@NotNull final String fileName) throws IOException {
+		final InputStream inputStream = MeshExamples.class.getResourceAsStream(fileName);
+		PSLG pslg = PSLGGenerator.toPSLGtoVShapes(inputStream);
+		DistanceFunctionApproxBF distFunctionApprox = new DistanceFunctionApproxBF(pslg, IDistanceFunction.create(pslg.getSegmentBound(), pslg.getHoles()));
+		distFunctionApprox.printPython();
+
+	}
 }

VadereMeshing/src/org/vadere/meshing/examples/EikMeshPlots.java

@@ -57,9 +57,11 @@ public class EikMeshPlots {
 
 		kaiserslautern();
 		ruppertsAndEikMeshKaiserslautern();*/
-		bridge();
+		//bridge();
 		//roomLFS();
 		//cornerLFS();
+
+		uniformRing(0.3);
 	}
 
 	public static void randomDelaunay() throws IOException {
@@ -432,9 +434,9 @@ public class EikMeshPlots {
 
 	private static void write(final String string, final String filename) throws IOException {
 		File outputFile = new File("./eikmesh/"+filename+".tex");
-		try(FileWriter fileWriter = new FileWriter(outputFile)) {
-			fileWriter.write(string);
-		}
+//		try(FileWriter fileWriter = new FileWriter(outputFile)) {
+			//fileWriter.write(string);
+//		}
 	}
 
 	private static String toTexDocument(final String tikz) {

VadereMeshing/src/org/vadere/meshing/examples/EikMeshPoly.java

@@ -5,6 +5,7 @@ import org.vadere.meshing.mesh.impl.PMeshPanel;
 import org.vadere.meshing.mesh.impl.PSLG;
 import org.vadere.meshing.mesh.triangulation.EdgeLengthFunctionApprox;
 import org.vadere.meshing.mesh.triangulation.improver.eikmesh.impl.PEikMesh;
+import org.vadere.meshing.mesh.triangulation.triangulator.impl.PRuppertsTriangulator;
 import org.vadere.meshing.utils.io.poly.PSLGGenerator;
 import org.vadere.meshing.utils.io.tex.TexGraphGenerator;
 import org.vadere.util.geometry.shapes.VPolygon;
@@ -27,13 +28,14 @@ public class EikMeshPoly {
 		//meshPoly("/poly/bridge.poly");
 		//meshPoly("/poly/room.poly");
 		//meshPoly("/poly/corner.poly");
+		//meshPoly("/poly/railing.poly");
 	}
 
 	public static void meshPoly(@NotNull final String fileName) throws IOException, InterruptedException {
 		final InputStream inputStream = MeshExamples.class.getResourceAsStream(fileName);
 		PSLG pslg = PSLGGenerator.toPSLGtoVShapes(inputStream);
 		EdgeLengthFunctionApprox edgeLengthFunctionApprox = new EdgeLengthFunctionApprox(pslg);
-		edgeLengthFunctionApprox.smooth(0.3);
+		edgeLengthFunctionApprox.smooth(0.4);
 		edgeLengthFunctionApprox.printPython();
 
 
@@ -41,26 +43,37 @@ public class EikMeshPoly {
 		VPolygon segmentBound = pslg.getSegmentBound();
 		IDistanceFunction distanceFunction = IDistanceFunction.create(segmentBound, holes);
 
+		var ruppert = new PRuppertsTriangulator(
+				pslg,
+				p -> Double.POSITIVE_INFINITY,
+				0,
+				true
+		);
+		ruppert.generate();
+
 		// (3) use EikMesh to improve the mesh
 		double h0 = 1.0;
 		var meshImprover = new PEikMesh(
 				distanceFunction,
 				edgeLengthFunctionApprox,
 				h0,
-				new VRectangle(segmentBound.getBounds2D()),
-				pslg.getHoles()
+				pslg.getBoundingBox(),
+				pslg.getAllPolygons()
 		);
 
-		var meshPanel = new PMeshPanel(meshImprover.getMesh(), 1000, 800);
+		var meshPanel = new PMeshPanel(meshImprover.getMesh()/*, f -> distanceFunction.apply(meshImprover.getMesh().toTriangle(f).midPoint()) > 0*/, 1000, 800);
 		meshPanel.display("Combined distance functions " + h0);
+		meshImprover.improve();
 		while (!meshImprover.isFinished()) {
-			meshImprover.improve();
-			Thread.sleep(20);
+			synchronized (meshImprover.getMesh()) {
+				meshImprover.improve();
+			}
+			//Thread.sleep(200);
 			meshPanel.repaint();
 		}
 		//meshImprover.generate();
 
-		write(toTexDocument(TexGraphGenerator.toTikz(meshImprover.getMesh(), f-> lightBlue, 1.0f)), "mesh.tex");
+		write(toTexDocument(TexGraphGenerator.toTikz(meshImprover.getMesh(), f-> lightBlue, 1.0f)), "mesh");
 		System.out.println(meshImprover.getMesh().getNumberOfVertices());
 
 		// display the mesh

VadereMeshing/src/org/vadere/meshing/examples/RuppertExamples.java

+package org.vadere.meshing.examples;
+
+import org.jetbrains.annotations.NotNull;
+import org.vadere.meshing.mesh.impl.PMeshPanel;
+import org.vadere.meshing.mesh.impl.PSLG;
+import org.vadere.meshing.mesh.triangulation.IEdgeLengthFunction;
+import org.vadere.meshing.mesh.triangulation.improver.eikmesh.impl.PEikMesh;
+import org.vadere.meshing.mesh.triangulation.triangulator.impl.PRuppertsTriangulator;
+import org.vadere.meshing.utils.io.poly.PSLGGenerator;
+import org.vadere.meshing.utils.io.tex.TexGraphGenerator;
+import org.vadere.util.geometry.shapes.VLine;
+import org.vadere.util.geometry.shapes.VPolygon;
+import org.vadere.util.math.IDistanceFunction;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Collection;
+
+public class RuppertExamples {
+
+	public static void main(String... args) throws InterruptedException, IOException {
+		rupperts("/poly/mf_small_very_simple.poly");
+	}
+
+	public static void rupperts(@NotNull final String fileName) throws IOException {
+		final InputStream inputStream = MeshExamples.class.getResourceAsStream(fileName);
+		PSLG pslg = PSLGGenerator.toPSLGtoVShapes(inputStream);
+		Collection<VLine> lines = pslg.getAllSegments();
+		Collection<VPolygon> holes = pslg.getHoles();
+		VPolygon segmentBound = pslg.getSegmentBound();
+
+		//IEdgeLengthFunction h = p -> 0.01 /*+ 0.2*Math.abs(distanceFunction.apply(p))*/;
+		var ruppert = new PRuppertsTriangulator(
+				pslg,
+				p -> Double.POSITIVE_INFINITY,
+				0,
+				false
+		);
+		//(mesh, f -> false, width, height, colorFunction
+		PMeshPanel panel = new PMeshPanel(ruppert.getMesh(), f -> ruppert.getMesh().getBooleanData(f, "boundary"),1000, 1000);
+		panel.display("Ruppert's Algorithm");
+		while (!ruppert.isFinished()) {
+			try {
+				Thread.sleep(200);
+			} catch (InterruptedException e) {
+				e.printStackTrace();
+			}
+
+			synchronized (ruppert.getMesh()) {
+				ruppert.step();
+			}
+			panel.repaint();
+		}
+
+		System.out.println(TexGraphGenerator.toTikz(ruppert.getMesh()));
+		System.out.println("finished");
+	}
+}

VadereMeshing/src/org/vadere/meshing/mesh/gen/MeshPanel.java

@@ -23,7 +23,8 @@ import javax.swing.*;
  */
 public class MeshPanel<V extends IVertex, E extends IHalfEdge, F extends IFace> extends Canvas {
 
-	private  MeshRenderer<V, E, F> meshRenderer;
+	private MeshRenderer<V, E, F> meshRenderer;
+	public static Function defaultFaceColors = f -> new Color(0.8584083044982699f, 0.9134486735870818f, 0.9645674740484429f);
 
 	/**
 	 * The width of the canvas.
@@ -121,7 +122,7 @@ public class MeshPanel<V extends IVertex, E extends IHalfEdge, F extends IFace>
 			@NotNull final IMesh<V, E, F> mesh,
 			final double width,
 			final double height) {
-		this(mesh, f -> false, width, height, f -> new Color(0.8584083044982699f, 0.9134486735870818f, 0.9645674740484429f), e -> Color.GRAY);
+		this(mesh, f -> false, width, height, defaultFaceColors, e -> Color.GRAY);
 	}
 
 	@Override

VadereMeshing/src/org/vadere/meshing/mesh/gen/MeshRenderer.java

@@ -172,10 +172,11 @@ public class MeshRenderer<V extends IVertex, E extends IHalfEdge, F extends IFac
 		for(F face : faces) {
 			VPolygon polygon = mesh.toPolygon(face);
 
-			if(faceColorFunction != null) {
+			if(alertPred.test(face)) {
+				graphics.setColor(new Color(200, 0, 0));
+			}
+			else if(faceColorFunction != null) {
 				graphics.setColor(faceColorFunction.apply(face));
-			} else if(alertPred.test(face)) {
-				graphics.setColor(new Color(100, 0, 0));
 			} else {
 				graphics.setColor(Color.GRAY);
 			}

VadereMeshing/src/org/vadere/meshing/mesh/inter/IMesh.java

@@ -368,11 +368,11 @@ public interface IMesh<V extends IVertex, E extends IHalfEdge, F extends IFace>
 	<CF> Optional<CF> getData(@NotNull F face, @NotNull final String name, @NotNull final Class<CF> clazz);
 
 	default boolean getBooleanData(@NotNull F face, @NotNull final String name) {
-		return getData(face, name, Boolean.class).or(null).get();
+		return getData(face, name, Boolean.class).orElse(false);
 	}
 
 	default double getDoubleData(@NotNull F face, @NotNull final String name) {
-		return getData(face, name, Double.class).or(null).get();
+		return getData(face, name, Double.class).orElse(0.0);
 	}
 
 	/**
@@ -1162,7 +1162,7 @@ public interface IMesh<V extends IVertex, E extends IHalfEdge, F extends IFace>
 	 * @return a parallel stream {@link Stream} of (all alive) interior faces
 	 */
 	default Stream<F> streamFaces() {
-		return streamFaces(f -> true);
+		return streamFaces(f -> !isBoundary(f));
 	}
 
 	/**
@@ -1316,7 +1316,7 @@ public interface IMesh<V extends IVertex, E extends IHalfEdge, F extends IFace>
 	 */
 	default VTriangle toTriangle(@NotNull final F face) {
 		List<V> vertices = getVertices(face);
-		assert vertices.size() == 3;
+		assert vertices.size() == 3 : "number of vertices of " + face + " is " + vertices.size();
 		return new VTriangle(new VPoint(vertices.get(0)), new VPoint(vertices.get(1)), new VPoint(vertices.get(2)));
 	}
 
@@ -1939,6 +1939,8 @@ public interface IMesh<V extends IVertex, E extends IHalfEdge, F extends IFace>
 		return Optional.empty();
 	}
 
+	//default Optional<E> getBoundaryEdge()
+
 	/**
 	 * Returns a deep clone of this mesh.
 	 *

VadereMeshing/src/org/vadere/meshing/mesh/inter/IPolyConnectivity.java

@@ -9,6 +9,7 @@ import org.vadere.util.geometry.shapes.IPoint;
 import org.vadere.util.logging.Logger;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Optional;
@@ -39,6 +40,7 @@ public interface IPolyConnectivity<V extends IVertex, E extends IHalfEdge, F ext
 	 */
 	Logger log = Logger.getLogger(IPolyConnectivity.class);
 
+
 	/**
 	 * <p>Returns the mesh of this poly-connectivity {@link IPolyConnectivity}.</p>
 	 *
@@ -553,6 +555,66 @@ public interface IPolyConnectivity<V extends IVertex, E extends IHalfEdge, F ext
 		return Optional.of(currentFace);
 	}
 
+	// TODO: improve performance by remembering faces
+	/**
+	 * <p>A virus like working algorithm which searches for neighbouring faces by starting at the face until
+	 * the <tt>markCondition</tt> does no longer hold or the maximal dept is reached.
+	 * This requires in the worst case O(n), where n is the number of edges of all involved faces
+	 * (i.e. the face and the merged faces).</p>
+	 *
+	 * <p>Does not changes the connectivity.</p>
+	 *
+	 * @param face                      the face
+	 * @param markCondition             the mark condition.
+	 * @param maxDept                   the maximum dept / neighbouring distance at which faces can be marked / found
+	 *
+	 * @return the merge result i.e. the resulting face.
+	 */
+	default List<F> findFaces(
+			@NotNull final F face,
+			@NotNull final Predicate<F> markCondition,
+			final int maxDept) {
+		int dept = 0;
+
+		if(!markCondition.test(face)) {
+			return Collections.EMPTY_LIST;
+		}
+
+		Set<F> markedFaces = new HashSet<>();
+		List<F> result = new ArrayList<>();
+		result.add(face);
+		markedFaces.add(face);
+
+		List<E> toProcess = getMesh().getEdges(face);
+
+		while (!toProcess.isEmpty()) {
+			dept++;
+
+			List<E> newToProcess = new ArrayList<>();
+			//assert toProcess.isEmpty() || toProcess.stream().anyMatch(e -> getMesh().getFace(e))) : "each edge of both faces is a link to the other face";
+
+			for(E edge : toProcess) {
+				// the face might be destroyed by an operation before
+				F candidate = getMesh().getTwinFace(edge);
+				if(!markedFaces.contains(candidate) &&  markCondition.test(candidate)) {
+					result.add(candidate);
+					markedFaces.add(candidate);
+					for(E e : getMesh().getEdgeIt(candidate)) {
+						newToProcess.add(e);
+					}
+				}
+			}
+
+			if(maxDept > 0 && dept >= maxDept) {
+				return result;
+			}
+
+			toProcess = newToProcess;
+		}
+
+		return result;
+	}
+
 	/**
 	 * Creates a new hole or extends an existing hole by removing neighbouring faces by a virus algorithm
 	 * which consumes faces as long as the merge condition holds.

VadereMeshing/src/org/vadere/meshing/mesh/inter/ITriConnectivity.java

@@ -2813,7 +2813,7 @@ public interface ITriConnectivity<V extends IVertex, E extends IHalfEdge, F exte
 		};
 
 		//log.debug(getMesh().streamFaces().filter(f -> !getMesh().isDestroyed(f)).filter(f -> !getMesh().isBoundary(f)).filter(e -> !orientationPredicate.test(e)).count() + " invalid triangles");
-		return getMesh().streamFaces().filter(f -> !getMesh().isDestroyed(f)).filter(f -> !getMesh().isBoundary(f)).allMatch(orientationPredicate);
+		return getMesh().streamFaces().filter(f -> !getMesh().isDestroyed(f)).allMatch(orientationPredicate);
 	}
 
 	/**

VadereMeshing/src/org/vadere/meshing/mesh/triangulation/DistanceFunctionApproxBF.java

+package org.vadere.meshing.mesh.triangulation;
+
+import org.jetbrains.annotations.NotNull;
+import org.vadere.meshing.mesh.gen.PFace;
+import org.vadere.meshing.mesh.gen.PHalfEdge;
+import org.vadere.meshing.mesh.gen.PVertex;
+import org.vadere.meshing.mesh.impl.PSLG;
+import org.vadere.meshing.mesh.inter.IIncrementalTriangulation;
+import org.vadere.meshing.mesh.triangulation.triangulator.impl.PRuppertsTriangulator;
+import org.vadere.util.geometry.GeometryUtils;
+import org.vadere.util.geometry.shapes.IPoint;
+import org.vadere.util.geometry.shapes.VRectangle;
+import org.vadere.util.math.IDistanceFunction;
+import org.vadere.util.math.InterpolationUtil;
+import java.util.function.Function;
+
+public class DistanceFunctionApproxBF implements IDistanceFunction {
+	private IIncrementalTriangulation<PVertex, PHalfEdge, PFace> triangulation;
+
+	private static final String propName = "distObs";
+
+	public DistanceFunctionApproxBF(
+			@NotNull final PSLG pslg,
+			@NotNull final Function<IPoint, Double> circumRadiusFunc,
+			@NotNull final IDistanceFunction exactDistanceFunc) {
+		//IPointConstructor<DataPoint<Double>> pointConstructor = (x, y) -> new DataPoint<>(x, y);
+		/**
+		 * Add a bound around so the edge function is also defined outside.
+		 */
+		VRectangle bound = GeometryUtils.boundRelative(pslg.getSegmentBound().getPoints(), 0.3);
+		PSLG boundedPSLG = pslg.conclose(bound);
+
+		var ruppertsTriangulator = new PRuppertsTriangulator(boundedPSLG, circumRadiusFunc, 10, false);
+		triangulation = ruppertsTriangulator.generate();
+
+		//TODO: maybe transform into an immutable triangulation / mesh!
+		triangulation.setCanIllegalPredicate(e -> true);
+
+		// compute and set the local feature size
+		var vertices = triangulation.getMesh().getVertices();
+
+		for(var v : vertices) {
+			double distance = exactDistanceFunc.apply(v);
+			triangulation.getMesh().setDoubleData(v, propName, distance);
+		}
+	}
+
+	public DistanceFunctionApproxBF(@NotNull final PSLG pslg, @NotNull final IDistanceFunction exactDistanceFunc) {
+		this(pslg, p -> Double.POSITIVE_INFINITY, exactDistanceFunc);
+		//IPointConstructor<DataPoint<Double>> pointConstructor = (x, y) -> new DataPoint<>(x, y);
+	}
+
+	@Override
+	public Double apply(@NotNull final IPoint p) {
+		var face = triangulation.locateFace(p.getX(), p.getY()).get();
+		var mesh = triangulation.getMesh();
+
+		if(mesh.isBoundary(face)) {
+			return Double.POSITIVE_INFINITY;
+		}
+		else {
+			double x[] = new double[3];
+			double y[] = new double[3];
+			double z[] = new double[3];
+
+			triangulation.getTriPoints(face, x, y, z, propName);
+
+			double totalArea = GeometryUtils.areaOfPolygon(x, y);
+
+			return InterpolationUtil.barycentricInterpolation(x, y, z, totalArea, p.getX(), p.getY());
+		}
+	}
+
+	public void printPython() {
+		System.out.println(triangulation.getMesh().toPythonTriangulation(v -> triangulation.getMesh().getDoubleData(v, propName)));
+		/*var points = triangulation.getMesh().getPoints();
+		System.out.print("[");
+		for(var dataPoint : points) {
+			System.out.print("["+dataPoint.getX()+","+dataPoint.getY()+"],");
+		}
+		System.out.println("]\n\n");
+
+		System.out.print("[");
+		for(var dataPoint : points) {
+			System.out.print(dataPoint.getData()+",");
+		}
+		System.out.println("]");*/
+	}
+}

VadereMeshing/src/org/vadere/meshing/mesh/triangulation/EdgeLengthFunctionApprox.java

@@ -43,17 +43,21 @@ public class EdgeLengthFunctionApprox implements IEdgeLengthFunction {
 
 		// compute and set the local feature size
 		var vertices = triangulation.getMesh().getVertices();
-
+		var mesh = triangulation.getMesh();
 		for(var v : vertices) {
 			double minEdgeLen = Double.MAX_VALUE;
-			for(var u : triangulation.getMesh().getAdjacentVertexIt(v)) {
-				double len = v.distance(u) * 0.9;
-				if(len < minEdgeLen) {
-					minEdgeLen = len;
+			for(var e : triangulation.getMesh().getEdges(v)) {
+				if(!mesh.getBooleanData(mesh.getFace(e), "boundary")
+						|| !mesh.getBooleanData(mesh.getTwinFace(e), "boundary")) {
+					var u = triangulation.getMesh().getTwinVertex(e);
+					double len = v.distance(u) * 0.9;
+					if(len < minEdgeLen) {
+						minEdgeLen = len;
+					}
 				}
 			}
 
-			triangulation.getMesh().setData(v, propName, minEdgeLen);
+			triangulation.getMesh().setDoubleData(v, propName, minEdgeLen);
 		}
 	}
 
@@ -67,21 +71,21 @@ public class EdgeLengthFunctionApprox implements IEdgeLengthFunction {
 		// smooth the function based such that it is g-Lipschitz
 		var mesh = triangulation.getMesh();
 		PriorityQueue<PVertex> heap = new PriorityQueue<>(
-				Comparator.comparingDouble(v1 -> mesh.getData(v1, propName, Double.class).get())
+				Comparator.comparingDouble(v1 -> mesh.getDoubleData(v1, propName))
 		);
 		heap.addAll(mesh.getVertices());
 
 		while (!heap.isEmpty()) {
 			var v = heap.poll();
-			double hv = mesh.getData(v, propName, Double.class).get();
+			double hv = mesh.getDoubleData(v, propName);
 			for (var u : mesh.getAdjacentVertexIt(v)) {
-				double hu = mesh.getData(u, propName, Double.class).get();
+				double hu = mesh.getDoubleData(u, propName);
 				double min = Math.min(hu, hv + g * v.distance(u));
 
 				// update heap
 				if (min < hu) {
 					heap.remove(u);
-					mesh.setData(u, propName, min);
+					mesh.setDoubleData(u, propName, min);
 					heap.add(u);
 				}
 			}
@@ -110,7 +114,7 @@ public class EdgeLengthFunctionApprox implements IEdgeLengthFunction {
 	}
 
 	public void printPython() {
-		System.out.println(triangulation.getMesh().toPythonTriangulation(v -> triangulation.getMesh().getData(v, propName, Double.class).get()));
+		System.out.println(triangulation.getMesh().toPythonTriangulation(v -> triangulation.getMesh().getDoubleData(v, propName)));
 		/*var points = triangulation.getMesh().getPoints();
 		System.out.print("[");
 		for(var dataPoint : points) {

VadereMeshing/src/org/vadere/meshing/mesh/triangulation/improver/eikmesh/impl/PEikMesh.java

@@ -59,7 +59,7 @@ public class PEikMesh extends GenEikMesh<PVertex, PHalfEdge, PFace> {
 			double initialEdgeLen,
 			@NotNull VRectangle bound
 	) {