first commit

hrmsEjb/net/sf/jasperreports/engine/fill/JRFloatVarianceIncrementer.java

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+package net.sf.jasperreports.engine.fill;
+
+class JRFloatVarianceIncrementer extends JRAbstractExtendedIncrementer {
+  private static JRFloatVarianceIncrementer mainInstance = new JRFloatVarianceIncrementer();
+  
+  public static JRFloatVarianceIncrementer getInstance() {
+    return mainInstance;
+  }
+  
+  public Object increment(JRCalculable variable, Object expressionValue, AbstractValueProvider valueProvider) {
+    Number value = (Number)variable.getIncrementedValue();
+    Number newValue = (Number)expressionValue;
+    if (newValue == null) {
+      if (variable.isInitialized())
+        return null; 
+      return value;
+    } 
+    if (value == null || variable.isInitialized())
+      return JRFloatIncrementerFactory.ZERO; 
+    Number countValue = (Number)valueProvider.getValue(variable.getHelperVariable((byte)0));
+    Number sumValue = (Number)valueProvider.getValue(variable.getHelperVariable((byte)1));
+    return new Float((countValue.floatValue() - 1.0F) * value.floatValue() / countValue.floatValue() + (sumValue.floatValue() / countValue.floatValue() - newValue.floatValue()) * (sumValue.floatValue() / countValue.floatValue() - newValue.floatValue()) / (countValue.floatValue() - 1.0F));
+  }
+  
+  public Object combine(JRCalculable calculable, JRCalculable calculableValue, AbstractValueProvider valueProvider) {
+    Number value = (Number)calculable.getIncrementedValue();
+    if (calculableValue.getValue() == null) {
+      if (calculable.isInitialized())
+        return null; 
+      return value;
+    } 
+    if (value == null || calculable.isInitialized())
+      return new Float(((Number)calculableValue.getIncrementedValue()).floatValue()); 
+    float v1 = value.floatValue();
+    float c1 = ((Number)valueProvider.getValue(calculable.getHelperVariable((byte)0))).floatValue();
+    float s1 = ((Number)valueProvider.getValue(calculable.getHelperVariable((byte)1))).floatValue();
+    float v2 = ((Number)calculableValue.getIncrementedValue()).floatValue();
+    float c2 = ((Number)valueProvider.getValue(calculableValue.getHelperVariable((byte)0))).floatValue();
+    float s2 = ((Number)valueProvider.getValue(calculableValue.getHelperVariable((byte)1))).floatValue();
+    c1 -= c2;
+    s1 -= s2;
+    float c = c1 + c2;
+    return new Float(c1 / c * v1 + c2 / c * v2 + c2 / c1 * s1 / c * s1 / c + c1 / c2 * s2 / c * s2 / c - 2.0F * s1 / c * s2 / c);
+  }
+  
+  public Object initialValue() {
+    return JRFloatIncrementerFactory.ZERO;
+  }
+}