| /* ==================================================================== |
| Licensed to the Apache Software Foundation (ASF) under one or more |
| contributor license agreements. See the NOTICE file distributed with |
| this work for additional information regarding copyright ownership. |
| The ASF licenses this file to You under the Apache License, Version 2.0 |
| (the "License"); you may not use this file except in compliance with |
| the License. You may obtain a copy of the License at |
| |
| http://www.apache.org/licenses/LICENSE-2.0 |
| |
| Unless required by applicable law or agreed to in writing, software |
| distributed under the License is distributed on an "AS IS" BASIS, |
| WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| See the License for the specific language governing permissions and |
| limitations under the License. |
| ==================================================================== */ |
| |
| package org.apache.poi.ss.formula.functions; |
| |
| import java.util.Arrays; |
| |
| import org.apache.poi.ss.formula.eval.ErrorEval; |
| import org.apache.poi.ss.formula.eval.EvaluationException; |
| import org.apache.poi.ss.formula.eval.NumberEval; |
| import org.apache.poi.ss.formula.eval.ValueEval; |
| |
| /** |
| * Calculates the net present value of an investment by using a discount rate |
| * and a series of future payments (negative values) and income (positive |
| * values). Minimum 2 arguments, first arg is the rate of discount over the |
| * length of one period others up to 254 arguments representing the payments and |
| * income. |
| * |
| * @author SPetrakovsky |
| * @author Marcel May |
| */ |
| public final class Npv implements Function { |
| |
| public ValueEval evaluate(ValueEval[] args, int srcRowIndex, int srcColumnIndex) { |
| int nArgs = args.length; |
| if (nArgs < 2) { |
| return ErrorEval.VALUE_INVALID; |
| } |
| |
| try { |
| double rate = NumericFunction.singleOperandEvaluate(args[0], srcRowIndex, srcColumnIndex); |
| // convert tail arguments into an array of doubles |
| ValueEval[] vargs = Arrays.copyOfRange(args, 1, args.length, ValueEval[].class); |
| double[] values = AggregateFunction.ValueCollector.collectValues(vargs); |
| |
| double result = FinanceLib.npv(rate, values); |
| NumericFunction.checkValue(result); |
| return new NumberEval(result); |
| } catch (EvaluationException e) { |
| return e.getErrorEval(); |
| } |
| } |
| } |