Package mondrian.olap.fun

Source Code of mondrian.olap.fun.VarPFunDef

/*
* 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.
* You must accept the terms of that agreement to use this software.
*
* Copyright (c) 2002-2013 Pentaho Corporation..  All rights reserved.
*/

package mondrian.olap.fun;

import mondrian.calc.*;
import mondrian.calc.impl.AbstractDoubleCalc;
import mondrian.calc.impl.ValueCalc;
import mondrian.mdx.ResolvedFunCall;
import mondrian.olap.*;

/**
* Definition of the <code>VarP</code> MDX builtin function
* (and its synonym <code>VarianceP</code>).
*
* @author jhyde
* @since Mar 23, 2006
*/
class VarPFunDef extends AbstractAggregateFunDef {
    static final Resolver VariancePResolver =
        new ReflectiveMultiResolver(
            "VarianceP",
            "VarianceP(<Set>[, <Numeric Expression>])",
            "Alias for VarP.",
            new String[]{"fnx", "fnxn"},
            VarPFunDef.class);

    static final Resolver VarPResolver =
        new ReflectiveMultiResolver(
            "VarP",
            "VarP(<Set>[, <Numeric Expression>])",
            "Returns the variance of a numeric expression evaluated over a set (biased).",
            new String[]{"fnx", "fnxn"},
            VarPFunDef.class);

    public VarPFunDef(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) {
                TupleList memberList = evaluateCurrentList(listCalc, evaluator);
                final int savepoint = evaluator.savepoint();
                try {
                    evaluator.setNonEmpty(false);
                    return
                        (Double) var(evaluator, memberList, calc, true);
                } finally {
                    evaluator.restore(savepoint);
                }
            }

            public boolean dependsOn(Hierarchy hierarchy) {
                return anyDependsButFirst(getCalcs(), hierarchy);
            }
        };
    }
}

// End VarPFunDef.java
TOP

Related Classes of mondrian.olap.fun.VarPFunDef

TOP
Copyright © 2018 www.massapi.com. All rights reserved.
All source code are property of their respective owners. Java is a trademark of Sun Microsystems, Inc and owned by ORACLE Inc. Contact coftware#gmail.com.