/*
// $Id: //open/mondrian-release/3.2/src/main/mondrian/olap/fun/VarFunDef.java#1 $
// This software is subject to the terms of the Eclipse Public License v1.0
// Agreement, available at the following URL:
// http://www.eclipse.org/legal/epl-v10.html.
// Copyright (C) 2006-2009 Julian Hyde
// All Rights Reserved.
// You must accept the terms of that agreement to use this software.
*/
package mondrian.olap.fun;
import mondrian.olap.*;
import mondrian.calc.Calc;
import mondrian.calc.ExpCompiler;
import mondrian.calc.ListCalc;
import mondrian.calc.impl.ValueCalc;
import mondrian.calc.impl.AbstractDoubleCalc;
import mondrian.mdx.ResolvedFunCall;
import java.util.List;
/**
* Definition of the <code>Var</code> MDX builtin function
* (and its synonym <code>Variance</code>).
*
* @author jhyde
* @version $Id: //open/mondrian-release/3.2/src/main/mondrian/olap/fun/VarFunDef.java#1 $
* @since Mar 23, 2006
*/
class VarFunDef extends AbstractAggregateFunDef {
static final Resolver VarResolver = new ReflectiveMultiResolver(
"Var",
"Var(<Set>[, <Numeric Expression>])",
"Returns the variance of a numeric expression evaluated over a set (unbiased).",
new String[]{"fnx", "fnxn"},
VarFunDef.class);
static final Resolver VarianceResolver = new ReflectiveMultiResolver(
"Variance", "Variance(<Set>[, <Numeric Expression>])",
"Alias for Var.",
new String[]{"fnx", "fnxn"},
VarFunDef.class);
public VarFunDef(FunDef dummyFunDef) {
super(dummyFunDef);
}
public Calc compileCall(ResolvedFunCall call, ExpCompiler compiler) {
final ListCalc listCalc =
compiler.compileList(call.getArg(0));
final Calc calc =
call.getArgCount() > 1
? compiler.compileScalar(call.getArg(1), true)
: new ValueCalc(call);
return new AbstractDoubleCalc(call, new Calc[] {listCalc, calc}) {
public double evaluateDouble(Evaluator evaluator) {
List memberList = evaluateCurrentList(listCalc, evaluator);
return (Double) var(
evaluator.push(false), memberList, calc, false);
}
public boolean dependsOn(Hierarchy hierarchy) {
return anyDependsButFirst(getCalcs(), hierarchy);
}
};
}
}
// End VarFunDef.java