24 lines
838 B
Java
24 lines
838 B
Java
package net.sf.jasperreports.engine.fill;
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class JRDoubleStandardDeviationIncrementer extends JRAbstractExtendedIncrementer {
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private static JRDoubleStandardDeviationIncrementer mainInstance = new JRDoubleStandardDeviationIncrementer();
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public static JRDoubleStandardDeviationIncrementer getInstance() {
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return mainInstance;
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}
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public Object increment(JRCalculable variable, Object expressionValue, AbstractValueProvider valueProvider) {
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if (expressionValue == null) {
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if (variable.isInitialized())
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return null;
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return variable.getValue();
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}
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Number varianceValue = (Number)valueProvider.getValue(variable.getHelperVariable((byte)2));
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return new Double(Math.sqrt(varianceValue.doubleValue()));
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}
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public Object initialValue() {
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return JRDoubleIncrementerFactory.ZERO;
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}
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}
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