more towards LDA tests

nking · Feb 8, 2016 · 175d2c8 · 175d2c8
1 parent 18b8053
commit 175d2c8
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diff --git a/src/algorithms/imageProcessing/util/MatrixUtil.java b/src/algorithms/imageProcessing/util/MatrixUtil.java
@@ -417,7 +417,7 @@ public static double[][] multiplyByTranspose(double[][] p, double[][] n) {
      * adapted from http://sebastianraschka.com/Articles/2014_python_lda.html
      * 
      * To apply the results to a data matrix, use y = W^T * X where W is
-     * the returned matrix.  
+     * the returned matrix (i.e., MatrixUtil.dot(w, data))
      * Note, X internally has been scaled to unit standard deviation.
      * @param data
      * @param classes
@@ -453,7 +453,7 @@ public static SimpleMatrix createLDATransformation(SimpleMatrix data,
      * adapted from http://sebastianraschka.com/Articles/2014_python_lda.html
      * 
      * To apply the results to a data matrix, use y = W^T * X where W is
-     * the returned matrix.  
+     * the returned matrix (i.e., MatrixUtil.dot(w, normData))
      * Note, X internally has been scaled to unit standard deviation.
      * @param normData  data scaled to mean of 0 and a standard deviation of 1
      * @param classes zero based transformed classes

diff --git a/tests/algorithms/imageProcessing/util/MatrixUtilTest.java b/tests/algorithms/imageProcessing/util/MatrixUtilTest.java
@@ -1,5 +1,6 @@
 package algorithms.imageProcessing.util;
 
+import algorithms.util.PolygonAndPointPlotter;
 import algorithms.util.ResourceFinder;
 import java.io.BufferedInputStream;
 import java.io.BufferedReader;
@@ -347,6 +348,133 @@ public void testCreateLDATrasformation() throws Exception {
         assertTrue(Math.abs(w2.get(1, 3) - 0.750) < 0.01);
 
 
+        int nr = w2.numRows();
+        int nc = w2.numCols();
+        int nr2 = normData.numRows();
+        int nc2 = normData.numCols();        
+        // 2 X 150
+        SimpleMatrix dataTransformed = new SimpleMatrix(MatrixUtil.dot(w, normData));
+
+        float minX = Float.MAX_VALUE;
+        float maxX = Float.MIN_VALUE;
+        float minY = Float.MAX_VALUE;
+        float maxY = Float.MIN_VALUE;
+        int[] countClasses = new int[nClasses];
+        for (int col = 0; col < dataTransformed.numCols(); ++col) {
+            int k = (int)Math.round(classes.get(0, col));
+            countClasses[k]++;
+            float x = (float)dataTransformed.get(0, col);
+            float y = (float)dataTransformed.get(1, col);
+            if (x < minX) {
+                minX = x;
+            }
+            if (y < minY) {
+                minY = y;
+            }
+            if (x < maxX) {
+                maxX = x;
+            }
+            if (y > maxY) {
+                maxY = y;
+            }
+        }
+        maxX = 3;
+        maxY = 3;
+
+        PolygonAndPointPlotter plotter = new PolygonAndPointPlotter(minX, maxX, 
+            minY, maxY);
+
+        for (int k = 0; k < nClasses; ++k) {
+            float[] xPoint = new float[countClasses[k]];
+            float[] yPoint = new float[countClasses[k]];
+            int count = 0;
+            for (int col = 0; col < dataTransformed.numCols(); ++col) {
+                if ((int)Math.round(classes.get(0, col)) != k) {
+                    continue;
+                }
+                xPoint[count] = (float)dataTransformed.get(0, col);
+                yPoint[count] = (float)dataTransformed.get(1, col);
+                count++;
+            }
+            float[] xPoly = null;
+            float[] yPoly = null;
+            plotter.addPlot(xPoint, yPoint, xPoly, yPoly, "class " + k);
+        }
+        String file1 = plotter.writeFile();
+
+        /*System.out.println(String.format("(%.3f, %.3f)", 
+                (float)dataTransformed.get(0, 0), 
+                (float)dataTransformed.get(1, 0)));
+        System.out.println(String.format("(%.3f, %.3f)", 
+                (float)dataTransformed.get(0, 1), 
+                (float)dataTransformed.get(1, 1)));
+        System.out.println(String.format("(%.3f, %.3f)", 
+                (float)dataTransformed.get(0, 2), 
+                (float)dataTransformed.get(1, 2)));*/
+
+        assertTrue(Math.abs(dataTransformed.get(0, 0) - 1.791) < 0.01);
+        assertTrue(Math.abs(dataTransformed.get(1, 0) - 0.115) < 0.01);
+
+        assertTrue(Math.abs(dataTransformed.get(0, 1) - 1.583) < 0.01);
+        assertTrue(Math.abs(dataTransformed.get(1, 1) - -0.265) < 0.01);
+
+        assertTrue(Math.abs(dataTransformed.get(0, 2) - 1.664) < 0.01);
+        assertTrue(Math.abs(dataTransformed.get(1, 2) - -0.084) < 0.01);
+
+        // --- to make a transformation usable on features not normalized:
+        SimpleMatrix w3 = MatrixUtil.createLDATransformation(
+            dataAndClasses[0], dataAndClasses[1]);
+        SimpleMatrix dataTransformed3 = new SimpleMatrix(MatrixUtil.dot(w3, 
+            dataAndClasses[0]));
+
+        minX = Float.MAX_VALUE;
+        maxX = Float.MIN_VALUE;
+        minY = Float.MAX_VALUE;
+        maxY = Float.MIN_VALUE;
+        countClasses = new int[nClasses];
+        for (int col = 0; col < dataTransformed3.numCols(); ++col) {
+            int k = (int)Math.round(classes.get(0, col));
+            countClasses[k]++;
+            float x = (float)dataTransformed3.get(0, col);
+            float y = (float)dataTransformed3.get(1, col);
+            if (x < minX) {
+                minX = x;
+            }
+            if (y < minY) {
+                minY = y;
+            }
+            if (x < maxX) {
+                maxX = x;
+            }
+            if (y > maxY) {
+                maxY = y;
+            }
+        }
+        maxX = -1*minX;
+        maxY = -1*minY;
+
+        PolygonAndPointPlotter plotter2 = new PolygonAndPointPlotter(minX, maxX, 
+            minY, maxY);
+
+        for (int k = 0; k < nClasses; ++k) {
+            float[] xPoint = new float[countClasses[k]];
+            float[] yPoint = new float[countClasses[k]];
+            int count = 0;
+            for (int col = 0; col < dataTransformed3.numCols(); ++col) {
+                if ((int)Math.round(classes.get(0, col)) != k) {
+                    continue;
+                }
+                xPoint[count] = (float)dataTransformed3.get(0, col);
+                yPoint[count] = (float)dataTransformed3.get(1, col);
+                count++;
+            }
+            float[] xPoly = null;
+            float[] yPoly = null;
+            plotter2.addPlot(xPoint, yPoint, xPoly, yPoly, "class " + k);
+        }
+        String file2 = plotter2.writeFile2();
+
+
     }
 
     private SimpleMatrix[] readIrisDataset() throws Exception {