org.randombits.confluence.metadata.expression.RoundFunction Maven / Gradle / Ivy
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package org.randombits.confluence.metadata.expression;
import org.randombits.math.eval.Cases;
import org.randombits.math.eval.Function;
import org.randombits.math.eval.Variable;
import org.randombits.math.eval.functions.FunctionParserExtension;
/**
* Rounds the first parameter to the number of decimal places specified in the
* second. Eg. 'round(12.3456, 2)==12.35' will evaluate to 'true'.
*
* @author David Peterson
* @version 1.0
*/
public class RoundFunction extends FunctionParserExtension {
private static final long serialVersionUID = 2336669910297123899L;
private static final String ROUND_NAME = "round";
/**
* Constructs a new RoundFunction.
*/
public RoundFunction() {
setName( ROUND_NAME );
}
public int getArity() {
return 2;
}
public double getVal( double[] arguments ) {
double newVal = arguments[0];
long decs = ( long ) arguments[1];
double xFactor = Math.pow( 10.0, decs );
newVal = ( double ) Math.round( newVal * xFactor ) / xFactor;
return newVal;
}
public double getValueWithCases( double[] arguments, Cases cases ) {
// I have no idea what cases are for, so I'm ignoring them...
return getVal( arguments );
}
public Function derivative( int wrt ) {
return new RoundFunction();
}
public Function derivative( Variable x ) {
return new RoundFunction();
}
public boolean dependsOn( Variable x ) {
return false;
}
}