Merge branch 'fixGetOrthocenterBug' into 'master'

getOrthocenter without slope determination

See merge request !49

VadereUtils/src/org/vadere/util/geometry/shapes/VTriangle.java

@@ -5,6 +5,10 @@ import java.util.stream.Stream;
 
 import org.jetbrains.annotations.NotNull;
 import org.vadere.util.geometry.GeometryUtils;
+import org.vadere.util.geometry.Vector3D;
+
+import static java.lang.Double.isInfinite;
+import static java.lang.Double.isNaN;
 
 /**
  * A triangle. Points must be given in counter clockwise manner to get correct
@@ -112,25 +116,58 @@ public class VTriangle extends VPolygon {
     }
 
     public VPoint getOrthocenter() {
+
         if(orthocenter == null) {
-            double slope = -1 / ((p2.getY() - p1.getY()) / (p2.getX() - p1.getX()));
-            // y  = slope * (x - p3.x) + p3.y
-
-            double slope2 = -1 / ((p1.getY() - p3.getY()) / (p1.getX() - p3.getX()));// y = slope2 * (x - p2.x) + p2.y
-
-            // slope2 * (x - p2.x) + p2.y  = slope * (x - p3.x) + p3.y
-            // slope2 * (x - p2.x) - slope * (x - p3.x)  =  + p3.y - p2.y
-            // slope2 * x - slope2 * p2.x - slope * x + slope * p3.x =  + p3.y - p2.y
-            // slope2 * x  - slope * x  =  + p3.y - p2.y + slope2 * p2.x - slope * p3.x
-            // x * (slope2 - slope) =  + p3.y - p2.y + slope2 * p2.x - slope * p3.x
-            double x = (p3.getY() - p2.getY() + slope2 * p2.getX() - slope * p3.getX()) / (slope2 - slope);
-            double y = slope * (x - p3.getX()) + p3.getY();
-            orthocenter = new VPoint(x, y);
+
+            VPoint p12, p13, p23, L1, L2;
+
+            // create edge vectors
+            p12 = p2.subtract(p1); // Vector2D better??
+            p13 = p3.subtract(p1);
+            p23 = p3.subtract(p2);
+
+            // create system of equations
+            double cross = p13.crossProduct(p12);
+
+            L1 = new VPoint(-cross* p23.getY() , cross * p23.getX() );
+            L2 = new VPoint(-cross* p13.getY() , cross * p13.getX() );
+
+            // solve system of equation (determine first element of resulting vector lamda with cramers rule; second element not necessary)
+            double lamda1 = ( p12.getX() * L2.getY() - p12.getY() * L2.getX() ) / ( L1.getX()*L2.getY() - L2.getX()*L1.getY() ) ;
+
+            orthocenter = new VPoint ( p1.add( L1.scalarMultiply(lamda1) ) );
         }
 
+        //VPoint orthocenter2 = getOrthocenterSlowImplementation() ;
+        //assert Math.abs( orthocenter.distance(orthocenter2)) < GeometryUtils.DOUBLE_EPS ;
         return orthocenter;
     }
 
+    public VPoint getOrthocenterSlowImplementation() {
+
+        // create edge vectors
+        VPoint p12 = p2.subtract(p1); // Vector2D better??
+        VPoint p13 = p3.subtract(p1);
+        VPoint p23 = p3.subtract(p2);
+
+        // edge vectors reverse
+        VPoint p21 = new VPoint(p12.scalarMultiply(-1.0));
+        VPoint p31 = new VPoint(p13.scalarMultiply(-1.0));
+        VPoint p32 = new VPoint(p23.scalarMultiply(-1.0));
+
+        // calculate angles a1, a2, a3
+        double a1 = Math.atan2(Math.abs( p13.crossProduct(p12)), p13.scalarProduct(p12)) ;
+        double a2 = Math.atan2(Math.abs( p23.crossProduct(p21)), p23.scalarProduct(p21)) ;
+        double a3 = Math.atan2(Math.abs( p31.crossProduct(p32)), p31.scalarProduct(p32)) ;
+
+        double div = Math.tan(a1)+ Math.tan(a2)+ Math.tan(a3) ;
+        double  x = ( Math.tan(a1)*p1.getX() + Math.tan(a2)*p2.getX() + Math.tan(a3)*p3.getX() ) / div;
+        double  y = ( Math.tan(a1)*p1.getY() + Math.tan(a2)*p2.getY() + Math.tan(a3)*p3.getY() ) / div;
+
+        return new VPoint(x,y);
+
+    }
+
     public VPoint closestPoint(final IPoint point) {
 
         VPoint currentClosest = null;

VadereUtils/tests/org/vadere/util/geometry/shapes/TestVTriangle.java

@@ -2,14 +2,9 @@ package org.vadere.util.geometry.shapes;
 
 import org.junit.After;
 import org.junit.Before;
-import org.junit.Ignore;
 import org.junit.Test;
 import org.vadere.util.geometry.GeometryUtils;
 import org.vadere.util.logging.Logger;
-
-import java.time.ZonedDateTime;
-import java.time.temporal.ChronoUnit;
-
 import static org.junit.Assert.*;
 
 public class TestVTriangle {
@@ -23,11 +18,10 @@ public class TestVTriangle {
     private double coorTop = Math.sqrt( Math.pow(radiusShould,2) + Math.pow(coor,2)  );
     private VTriangle vTriangle_symY_60degree = new VTriangle(new VPoint(-coor,-radiusShould), new VPoint(coor,-radiusShould), new VPoint(0.,coorTop) );
 
-
     // create y-symmetric 45°-45°-90°-triangle (90°-angle is split by y-axis)
     private VPoint vPoint1 = new VPoint(-1.,0.);
     private VPoint vPoint2 = new VPoint(1.,0.);
-    private VPoint vPoint3 = new VPoint(0.,1.);
+    private VPoint vPoint3 = new VPoint(0.,1);
     private VTriangle vTriangle_sym = new VTriangle(vPoint1, vPoint2, vPoint3);
 
     private VPoint vPoint4 = new VPoint(vPoint2.getX() + 0.1,vPoint2.getY()); // getter not necessary because attributes are public
@@ -40,23 +34,13 @@ public class TestVTriangle {
 
     @Before
     public void setUp() throws Exception {
-        // ?
     }
     @Test
     public void testClosestPoint0(){
-        // also write time stemp because it is not included into ASCI output file VadereUtils/log.out
-        logger.info("Start Test testClosestPoint" + ZonedDateTime.now().toLocalTime().truncatedTo(ChronoUnit.SECONDS));
-        System.out.println( "Point 1 == Point 2");
-        System.out.println( vTriangle_sym.closestPoint(vPoint1).equals(vPoint2,0.1) );
-        System.out.println( "Point 2 == Point 2");
-        System.out.println( vTriangle_sym.closestPoint(vPoint2).equals(vPoint2,0.1) );
-        System.out.println( "Point 2 == Point 4; accurate");
-        System.out.println( vTriangle_sym.closestPoint(vPoint2).equals(vPoint4,0.1) );
-        System.out.println( "Point 2 == Point 4; not accurate");
-        System.out.println( vTriangle_sym.closestPoint(vPoint2).equals(vPoint4,0.2) );
-
-        //double d1 = GeometryUtils.ccw(vPoint1, vPoint2, vPoint3);
-
+        assertFalse( vTriangle_sym.closestPoint(vPoint1).equals(vPoint2,0.1) );
+        assertTrue( vTriangle_sym.closestPoint(vPoint2).equals(vPoint2,0.1) );
+        assertFalse( vTriangle_sym.closestPoint(vPoint2).equals(vPoint4,0.1) );
+        assertTrue( vTriangle_sym.closestPoint(vPoint2).equals(vPoint4,0.2) );
     }
 
     /**
@@ -65,13 +49,6 @@ public class TestVTriangle {
      */
     @Test
     public void testContains() {
-        /*
-        System.out.println( "Point 1 - 3 belong to the triangle; should be true" );
-        System.out.println( vTriangle_sym.contains(vPoint1) && vTriangle_sym.contains(vPoint2) && vTriangle_sym.contains(vPoint3) );
-        System.out.println( "Point 2 - 4 belong to the triangle; should be false" );
-        System.out.println( vTriangle_sym.contains(vPoint2) && vTriangle_sym.contains(vPoint3) && vTriangle_sym.contains(vPoint4) );
-        */
-
         // vTriangle_sym.contains returns true if point is a vertex or point is inside triangle
         assertTrue("Point 1 is vertex of Triangle 1.",  vTriangle_sym.contains(vPoint1));
         assertTrue("Point 2 is vertex of Triangle 1.",  vTriangle_sym.contains(vPoint2));
@@ -88,15 +65,6 @@ public class TestVTriangle {
      */
     @Test
     public void testIsPartOf() {
-        /*
-        System.out.println( "Point 1 is in triangle; should be true" );
-        System.out.println( vTriangle_sym.isPartOf(vPoint1,0.0));
-        System.out.println( "Point 4 is in triangle; should be true" );
-        System.out.println( vTriangle_sym.isPartOf(vPoint4,0.2));
-        System.out.println( "Point 4 is in triangle; should be false" );
-        System.out.println( vTriangle_sym.isPartOf(vPoint4,0.1));
-        System.out.println( vTriangle_sym.isPartOf(vPoint5,0.01));*/
-
         // vTriangle_sym.isPartOf returns true if point is a vertex or point is inside triangle + tolerance
         double tolerance = 0.0;
         assertTrue("Point 1 is vertex of Triangle 1.", vTriangle_sym.isPartOf(vPoint1,tolerance));
@@ -106,7 +74,6 @@ public class TestVTriangle {
 
         // vTriangle_sym.isPartOf returns false if point is outside triangle + tolerance
         assertFalse("Point 4 lays outside Triangle 1.", vTriangle_sym.isPartOf(vPoint4,tolerance));
-
     }
 
     @Test
@@ -115,19 +82,9 @@ public class TestVTriangle {
         double x = vPoint.getX();
         double y = vPoint.getY();
         double eps = Math.max (Math.abs(x - 0.0), Math.abs(y - 1./3));
-
-        System.out.print( vPoint.toString() );
-        if (eps > GeometryUtils.DOUBLE_EPS) System.out.print( " is not Midpoint. Error \n");
-        else System.out.print( " is Midpoint. \n" );
         assertTrue(eps < GeometryUtils.DOUBLE_EPS);
     }
 
-    @Test
-    public void testMidPointA() {
-        VPoint vPoint = vTriangle_sym.midPoint();
-        VPoint checkPoint = new VPoint(0.0, 1./3);
-        assertEquals(checkPoint,vPoint);
-    }
 
     @Test
     public void testIsLine() {
@@ -143,8 +100,7 @@ public class TestVTriangle {
     @Test
     public void testGetCentroid() {
         VPoint vPoint = vTriangle_sym.getCentroid();
-        // special structure of triangle: midpoint = centroid
-        VPoint checkPoint = new VPoint(0.0, 1./3);
+        VPoint checkPoint = new VPoint(0.0, 1./3); // special structure of triangle: midpoint = centroid
         assertEquals(checkPoint,vPoint);
     }
 
@@ -158,33 +114,66 @@ public class TestVTriangle {
         //assertEquals(vPoint, new VPoint(0.0,0.0), GeometryUtils.DOUBLE_EPS);
         double eps = Math.max (Math.abs(x - 0.0), Math.abs(y - 0.0)); // Point (0,0) is incenter
         assertTrue(eps < GeometryUtils.DOUBLE_EPS);
-       // assertEquals(0.0, vPoint.distance(new VPoint(x, y)), GeometryUtils.DOUBLE_EPS);
 
     }
 
-    /**
-     * test fails because slope is infinite
-     * */
-    @Ignore
     @Test
     public void testGetOrthocenter() {
-
-        // use 60°-triangle (2 vertices on y-axis) for test
-        VPoint vPoint = vTriangle_60degree.getOrthocenter();
+        // time measure
+        long startTime, runTimeInNs, runTimeInNsSlow;
+        VPoint vPointY, vPoint;
+
+        /** Triangle 1: use 60°-triangle (2 vertices on y-axis) for test */
+        // fast implementation
+        startTime = System.nanoTime();
+        vPoint = vTriangle_60degree.getOrthocenter();
+        runTimeInNs = System.nanoTime() - startTime ;
         double x = vPoint.getX();
         double y = vPoint.getY();
         double eps = Math.max (Math.abs(x - 0.5), Math.abs(y - 0.0)); // Point (0.5,0) is orthocenter
         assertTrue(eps < GeometryUtils.DOUBLE_EPS);
 
-        // triangle with y-symmetry (45°-90°-45°); does not work because of infinite slope
-        // exception handling ?
-        VPoint vPointY = this.vTriangle_sym.getOrthocenter();
+        // slow implementation
+        startTime = System.nanoTime();
+        vPoint = vTriangle_60degree.getOrthocenterSlowImplementation();
+        runTimeInNsSlow = System.nanoTime() - startTime ;
+        x = vPoint.getX();
+        y = vPoint.getY();
+        eps = Math.max (Math.abs(x - 0.5), Math.abs(y - 0.0)); // Point (0.5,0) is orthocenter
+        assertTrue(eps < GeometryUtils.DOUBLE_EPS);
 
+        // compare fast and slow implementation
+        logger.info("Triangle 1: Fast implementation required " + runTimeInNs + "[nano sec]");
+        logger.info("Triangle 1: Slow implementation required " + runTimeInNsSlow + "[nano sec]");
+        logger.info("Triangle 1: time factor -> slow to fast: " + 1.0*runTimeInNsSlow/runTimeInNs );
+
+        /** Triangle 2:  triangle with y-symmetry (45°-90°-45°); does not work because of infinite slope */
+        // fast implementation
+        startTime = System.nanoTime();
+        vPointY= this.vTriangle_sym.getOrthocenter();
+        runTimeInNs = System.nanoTime() - startTime ;
+        x = vPointY.getX();
+        y = vPointY.getY();
+        eps = Math.max (Math.abs(x - 0.0), Math.abs(y - 1.0)); // Point (0.5,0) is orthocenter
+        assertTrue(eps < GeometryUtils.DOUBLE_EPS);
+
+        // slow implementation
+        startTime = System.nanoTime();
+        vPointY = this.vTriangle_sym.getOrthocenterSlowImplementation();
+        runTimeInNsSlow = System.nanoTime() - startTime ;
+        x = vPointY.getX();
+        y = vPointY.getY();
+        eps = Math.max (Math.abs(x - 0.0), Math.abs(y - 1.0)); // Point (0.5,0) is orthocenter
+        assertTrue(eps < GeometryUtils.DOUBLE_EPS);
+
+        // compare fast and slow implementation
+        logger.info("Triangle 2: Fast implementation required " + runTimeInNs + "[nano sec]");
+        logger.info("Triangle 2: Slow implementation required " + runTimeInNsSlow + "[nano sec]");
+        logger.info("Triangle 2: time factor -> slow to fast: " + 1.0*runTimeInNsSlow/runTimeInNs );
     }
 
     @Test
     public void testClosestPoint() {
-
         // y-symmetric triangle contains vPoint1
         assertEquals(vTriangle_sym.closestPoint(vPoint1), vPoint1 );
 
@@ -205,20 +194,17 @@ public class TestVTriangle {
         y = newPoint3.getY();
         eps = Math.max (Math.abs(x - 0.0), Math.abs(y - 0.3));
         assertTrue(eps < GeometryUtils.DOUBLE_EPS);
-
     }
 
 
     @Test
     public void testGetCircumcenter(){
-
-        // y-symmetric 60°-triangle: Circumcenter = Incenter = (0.0,0.0)
+        // y-symmetric 60°-triangle: Circumcenter = (0.0,0.0)
         VPoint vPoint = vTriangle_symY_60degree.getIncenter();
         double x = vPoint.getX();
         double y = vPoint.getY();
         double eps = Math.max (Math.abs(x - 0.0), Math.abs(y - 0.0));
         assertTrue(eps < GeometryUtils.DOUBLE_EPS);
-
     }
 
     @Test
@@ -229,17 +215,6 @@ public class TestVTriangle {
         assertTrue(eps < GeometryUtils.DOUBLE_EPS);
     }
 
-    /*
-    @Test
-    public void testIsInCircumscribedCycle() {
-    }
-    @Test
-    public void testMaxCoordinate() {
-    }
-    @Test
-    public void testGetLines() {
-    } */
-
     @After
     public void tearDown() throws Exception {
     }