001/* 002// This software is subject to the terms of the Eclipse Public License v1.0 003// Agreement, available at the following URL: 004// http://www.eclipse.org/legal/epl-v10.html. 005// You must accept the terms of that agreement to use this software. 006// 007// Copyright (C) 2006-2011 Pentaho 008// All Rights Reserved. 009*/ 010package mondrian.olap.fun; 011 012import mondrian.calc.*; 013import mondrian.calc.impl.AbstractDoubleCalc; 014import mondrian.calc.impl.ValueCalc; 015import mondrian.mdx.ResolvedFunCall; 016import mondrian.olap.*; 017 018/** 019 * Definition of the <code>VarP</code> MDX builtin function 020 * (and its synonym <code>VarianceP</code>). 021 * 022 * @author jhyde 023 * @since Mar 23, 2006 024 */ 025class VarPFunDef extends AbstractAggregateFunDef { 026 static final Resolver VariancePResolver = 027 new ReflectiveMultiResolver( 028 "VarianceP", 029 "VarianceP(<Set>[, <Numeric Expression>])", 030 "Alias for VarP.", 031 new String[]{"fnx", "fnxn"}, 032 VarPFunDef.class); 033 034 static final Resolver VarPResolver = 035 new ReflectiveMultiResolver( 036 "VarP", 037 "VarP(<Set>[, <Numeric Expression>])", 038 "Returns the variance of a numeric expression evaluated over a set (biased).", 039 new String[]{"fnx", "fnxn"}, 040 VarPFunDef.class); 041 042 public VarPFunDef(FunDef dummyFunDef) { 043 super(dummyFunDef); 044 } 045 046 public Calc compileCall(ResolvedFunCall call, ExpCompiler compiler) { 047 final ListCalc listCalc = 048 compiler.compileList(call.getArg(0)); 049 final Calc calc = 050 call.getArgCount() > 1 051 ? compiler.compileScalar(call.getArg(1), true) 052 : new ValueCalc(call); 053 return new AbstractDoubleCalc(call, new Calc[] {listCalc, calc}) { 054 public double evaluateDouble(Evaluator evaluator) { 055 TupleList memberList = evaluateCurrentList(listCalc, evaluator); 056 final int savepoint = evaluator.savepoint(); 057 try { 058 evaluator.setNonEmpty(false); 059 return 060 (Double) var(evaluator, memberList, calc, true); 061 } finally { 062 evaluator.restore(savepoint); 063 } 064 } 065 066 public boolean dependsOn(Hierarchy hierarchy) { 067 return anyDependsButFirst(getCalcs(), hierarchy); 068 } 069 }; 070 } 071} 072 073// End VarPFunDef.java