first commit

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

@@ -0,0 +1,54 @@
+package net.sf.jasperreports.engine.fill;
+
+import java.math.BigDecimal;
+
+class JRBigDecimalVarianceIncrementer extends JRAbstractExtendedIncrementer {
+  private static JRBigDecimalVarianceIncrementer mainInstance = new JRBigDecimalVarianceIncrementer();
+  
+  public static JRBigDecimalVarianceIncrementer getInstance() {
+    return mainInstance;
+  }
+  
+  public Object increment(JRCalculable variable, Object expressionValue, AbstractValueProvider valueProvider) {
+    BigDecimal value = (BigDecimal)variable.getIncrementedValue();
+    BigDecimal newValue = (BigDecimal)expressionValue;
+    if (newValue == null) {
+      if (variable.isInitialized())
+        return null; 
+      return value;
+    } 
+    if (value == null || variable.isInitialized())
+      return JRBigDecimalIncrementerFactory.ZERO; 
+    BigDecimal countValue = (BigDecimal)valueProvider.getValue(variable.getHelperVariable((byte)0));
+    BigDecimal sumValue = (BigDecimal)valueProvider.getValue(variable.getHelperVariable((byte)1));
+    return countValue.subtract(JRBigDecimalIncrementerFactory.ONE).multiply(value).divide(countValue, 4).add(sumValue.divide(countValue, 4).subtract(newValue).multiply(sumValue.divide(countValue, 4).subtract(newValue)).divide(countValue.subtract(JRBigDecimalIncrementerFactory.ONE), 4));
+  }
+  
+  public Object combine(JRCalculable calculable, JRCalculable calculableValue, AbstractValueProvider valueProvider) {
+    BigDecimal value = (BigDecimal)calculable.getIncrementedValue();
+    if (calculableValue.getValue() == null) {
+      if (calculable.isInitialized())
+        return null; 
+      return value;
+    } 
+    if (value == null || calculable.isInitialized())
+      return calculableValue.getIncrementedValue(); 
+    BigDecimal v1 = value;
+    BigDecimal c1 = (BigDecimal)valueProvider.getValue(calculable.getHelperVariable((byte)0));
+    BigDecimal s1 = (BigDecimal)valueProvider.getValue(calculable.getHelperVariable((byte)1));
+    BigDecimal v2 = (BigDecimal)calculableValue.getIncrementedValue();
+    BigDecimal c2 = (BigDecimal)valueProvider.getValue(calculableValue.getHelperVariable((byte)0));
+    BigDecimal s2 = (BigDecimal)valueProvider.getValue(calculableValue.getHelperVariable((byte)1));
+    c1 = c1.subtract(c2);
+    s1 = s1.subtract(s2);
+    BigDecimal c = c1.add(c2);
+    BigDecimal x1 = s1.divide(c, 4);
+    BigDecimal x2 = s2.divide(c, 4);
+    BigDecimal x3 = x1.multiply(x2);
+    return c1.divide(c, 4).multiply(v1).add(c2.divide(c, 4).multiply(v2)).add(c2.divide(c1, 4).multiply(x1).multiply(x1)).add(c1.divide(c2, 4).multiply(x2).multiply(x2)).subtract(x3).subtract(x3);
+  }
+  
+  public Object initialValue() {
+    return JRBigDecimalIncrementerFactory.ZERO;
+  }
+}