src/scratchpad/src/org/apache/poi/hssf/record/formula/functions/Pmt.java

   1 /*
   2 * Licensed to the Apache Software Foundation (ASF) under one or more
   3 * contributor license agreements.  See the NOTICE file distributed with
   4 * this work for additional information regarding copyright ownership.
   5 * The ASF licenses this file to You under the Apache License, Version 2.0
   6 * (the "License"); you may not use this file except in compliance with
   7 * the License.  You may obtain a copy of the License at
   8 *
   9 *     http://www.apache.org/licenses/LICENSE-2.0
  10 *
  11 * Unless required by applicable law or agreed to in writing, software
  12 * distributed under the License is distributed on an "AS IS" BASIS,
  13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14 * See the License for the specific language governing permissions and
  15 * limitations under the License.
  16 */
  17 package org.apache.poi.hssf.record.formula.functions;
  18
  19 import org.apache.poi.hssf.record.formula.eval.BoolEval;
  20 import org.apache.poi.hssf.record.formula.eval.ErrorEval;
  21 import org.apache.poi.hssf.record.formula.eval.Eval;
  22 import org.apache.poi.hssf.record.formula.eval.EvaluationException;
  23 import org.apache.poi.hssf.record.formula.eval.NumberEval;
  24 import org.apache.poi.hssf.record.formula.eval.NumericValueEval;
  25 import org.apache.poi.hssf.record.formula.eval.ValueEval;
  26
  27 /**
  28  * Implementation for the PMT() Excel function.<p/>
  29  *
  30  * <b>Syntax:</b><br/>
  31  * <b>PMT</b>(<b>rate</b>, <b>nper</b>, <b>pv</b>, fv, type)<p/>
  32  *
  33  * Returns the constant repayment amount required for a loan assuming a constant interest rate.<p/>
  34  *
  35  * <b>rate</b> the loan interest rate.<br/>
  36  * <b>nper</b> the number of loan repayments.<br/>
  37  * <b>pv</b> the present value of the future payments (or principle).<br/>
  38  * <b>fv</b> the future value (default zero) surplus cash at the end of the loan lifetime.<br/>
  39  * <b>type</b> whether payments are due at the beginning(1) or end(0 - default) of each payment period.<br/>
  40  *
  41  */
  42 public final class Pmt extends FinanceFunction {
  43
  44         public Eval evaluate(Eval[] args, int srcRow, short srcCol) {
  45
  46                 if(args.length < 3 || args.length > 5) {
  47                         return ErrorEval.VALUE_INVALID;
  48                 }
  49
  50                 try {
  51                         // evaluate first three (always present) args
  52                         double rate = evalArg(args[0], srcRow, srcCol);
  53                         double nper = evalArg(args[1], srcRow, srcCol);
  54                         double pv  = evalArg(args[2], srcRow, srcCol);
  55                         double fv = 0;
  56                         boolean arePaymentsAtPeriodBeginning = false;
  57
  58                         switch (args.length) {
  59                                 case 5:
  60                                         ValueEval ve = singleOperandNumericAsBoolean(args[4], srcRow, srcCol);
  61                                         if (ve instanceof ErrorEval) {
  62                                                 return ve;
  63                                         }
  64                                         arePaymentsAtPeriodBeginning = ((BoolEval) ve).getBooleanValue();
  65                                 case 4:
  66                                         fv = evalArg(args[3], srcRow, srcCol);
  67                         }
  68                         double d = FinanceLib.pmt(rate, nper, pv, fv, arePaymentsAtPeriodBeginning);
  69                         if (Double.isNaN(d)) {
  70                                 return (ValueEval) ErrorEval.VALUE_INVALID;
  71                         }
  72                         if (Double.isInfinite(d)) {
  73                                 return (ValueEval) ErrorEval.NUM_ERROR;
  74                         }
  75                         return new NumberEval(d);
  76                 } catch (EvaluationException e) {
  77                         return e.getErrorEval();
  78                 }
  79         }
  80
  81         private double evalArg(Eval arg, int srcRow, short srcCol) throws EvaluationException {
  82                 ValueEval ve = singleOperandEvaluate(arg, srcRow, srcCol);
  83                 if(ve instanceof ErrorEval) {
  84                         throw new EvaluationException((ErrorEval) ve);
  85                 }
  86                 if (ve instanceof NumericValueEval) {
  87                         return ((NumericValueEval) ve).getNumberValue();
  88                 }
  89                 throw new EvaluationException(ErrorEval.VALUE_INVALID);
  90         }
  91 }