Added GrokkingSlidingWindow.

CunningDJ · CunningDJ · commit 2dbd1c1767e7 · 2022-05-09T19:46:46.000-04:00
diff --git a/GrokkingSlidingWindow.java b/GrokkingSlidingWindow.java
@@ -0,0 +1,40 @@
+package com.cunningdj.grokJava;
+
+class GrokkingSlidingWindow {
+	public static void main(String[] args) {
+		Tester tester = new Tester();
+		String testTitle="";
+
+		// TEST CLASS METHODS HERE USING TESTER CLASS
+		// WINDOW_AVERAGE
+		testTitle = "WINDOW_AVERAGE";
+		tester.testDoubleArrayEquals(new double[]{2,3,4,5}, slidingAverage(new int[]{1,2,3,4,5,6}, 3), testTitle);
+		tester.testDoubleArrayEquals(new double[]{3.5}, slidingAverage(new int[]{1,2,3,4,5,6}, 6), testTitle);
+		tester.testDoubleArrayEquals(new double[]{1.5,2.5,3.5,4.5,5.5}, slidingAverage(new int[]{1,2,3,4,5,6}, 2), testTitle);
+	}
+
+	public static double[] slidingAverage(int[] values, int windowSize) {
+		if (windowSize > values.length) {
+			return null;
+		}
+		//  1 2 3 4 5 6
+		double windowSizeDouble = windowSize;
+		double[] averages = new double[values.length - windowSize + 1];
+		int averagesIdx = 0;
+		double currAvg = 0;
+		int i=0;
+		while (i < windowSize) {
+			currAvg += values[i];
+			++i;
+		}
+		currAvg = currAvg / windowSizeDouble;
+		averages[averagesIdx] = currAvg;
+		while (i < values.length) {
+			averagesIdx += 1;
+			currAvg += (values[i] / windowSizeDouble) - (values[i-windowSize] / windowSizeDouble);
+			averages[averagesIdx] = currAvg;
+			++i;
+		}
+		return averages;
+	}
+}
diff --git a/Tester.java b/Tester.java
@@ -41,6 +41,22 @@ public void testEquals(Object expected, Object actual, String testTitle) {
         }
     }
 
+    public void testDoubleArrayEquals(double[] expected, double[] actual, String testTitle) {
+        if (Arrays.equals(expected, actual)) {
+            printTestSuccess(testTitle);
+        } else {
+            printTestFailure(testTitle, toString(expected), toString(actual));
+        }
+    }
+
+    public void testFloatArrayEquals(float[] expected, float[] actual, String testTitle) {
+        if (Arrays.equals(expected, actual)) {
+            printTestSuccess(testTitle);
+        } else {
+            printTestFailure(testTitle, toString(expected), toString(actual));
+        }
+    }
+
     public void testIntArrayEquals(int[] expected, int[] actual, String testTitle) {
         if (Arrays.equals(expected, actual)) {
             printTestSuccess(testTitle);
@@ -71,6 +87,34 @@ private static String toString(int[] values) {
         return str;
     }
 
+    private static String toString(float[] values) {
+        if (values == null) {
+            return "null";
+        }
+        if (values.length < 1) {
+            return "";
+        }
+        String str = String.valueOf(values[0]);
+        for (int i=1; i < values.length; ++i) {
+            str += "-" + String.valueOf(values[i]);
+        }
+        return str;
+    }
+
+    private static String toString(double[] values) {
+        if (values == null) {
+            return "null";
+        }
+        if (values.length < 1) {
+            return "";
+        }
+        String str = String.valueOf(values[0]);
+        for (int i=1; i < values.length; ++i) {
+            str += "-" + String.valueOf(values[i]);
+        }
+        return str;
+    }
+
     private static String toString(List<List<Integer>> allValues) {
         if (allValues == null) {
             return "null";
