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Add implementation of RATE from patch in bug #52050 

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1186111 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Nick Burch 2011-10-19 11:32:44 +00:00
parent ecad01a716
commit cf1c5ee9e1
3 changed files with 121 additions and 0 deletions
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1
src/documentation/content/xdocs/status.xml
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@ -34,6 +34,7 @@
<changes>
<release version="3.8-beta5" date="2011-??-??">
<action dev="poi-developers" type="add">52050 - Support for the Excel RATE function</action>
<action dev="poi-developers" type="fix">51566 - HSLF fix for finishing parsing the picture stream on the first non-valid type</action>
<action dev="poi-developers" type="fix">51974 - Avoid HWPF issue when identifying the picture type</action>
<action dev="poi-developers" type="fix">52035 - Fix signed issue with very large word 6 files</action>

1
src/java/org/apache/poi/ss/formula/eval/FunctionEval.java
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@ -102,6 +102,7 @@ public final class FunctionEval {
retval[58] = FinanceFunction.NPER;
retval[59] = FinanceFunction.PMT;
retval[60] = new Rate();
retval[62] = new Irr();
retval[63] = NumericFunction.RAND;
retval[64] = new Match();

119
src/java/org/apache/poi/ss/formula/functions/Rate.java Normal file
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@ -0,0 +1,119 @@
/* ====================================================================
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 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.OperandResolver;
import org.apache.poi.ss.formula.eval.ValueEval;
/**
* Implements the Excel Rate function
*/
public class Rate implements Function {
public ValueEval evaluate(ValueEval[] args, int srcRowIndex, int srcColumnIndex) {
if (args.length < 3) { //First 3 parameters are mandatory
return ErrorEval.VALUE_INVALID;
}
double periods, payment, present_val, future_val = 0, type = 0, estimate = 0.1, rate;
try {
ValueEval v1 = OperandResolver.getSingleValue(args[0], srcRowIndex, srcColumnIndex);
ValueEval v2 = OperandResolver.getSingleValue(args[1], srcRowIndex, srcColumnIndex);
ValueEval v3 = OperandResolver.getSingleValue(args[2], srcRowIndex, srcColumnIndex);
ValueEval v4 = null;
if (args.length >= 4)
v4 = OperandResolver.getSingleValue(args[3], srcRowIndex, srcColumnIndex);
ValueEval v5 = null;
if (args.length >= 5)
v5 = OperandResolver.getSingleValue(args[4], srcRowIndex, srcColumnIndex);
ValueEval v6 = null;
if (args.length >= 6)
v6 = OperandResolver.getSingleValue(args[5], srcRowIndex, srcColumnIndex);
periods = OperandResolver.coerceValueToDouble(v1);
payment = OperandResolver.coerceValueToDouble(v2);
present_val = OperandResolver.coerceValueToDouble(v3);
if (args.length >= 4)
future_val = OperandResolver.coerceValueToDouble(v4);
if (args.length >= 5)
type = OperandResolver.coerceValueToDouble(v5);
if (args.length >= 6)
estimate = OperandResolver.coerceValueToDouble(v6);
rate = calculateRate(periods, payment, present_val, future_val, type, estimate) ;
checkValue(rate);
} catch (EvaluationException e) {
e.printStackTrace() ;
return e.getErrorEval();
}
return new NumberEval( rate ) ;
}
private double calculateRate(double nper, double pmt, double pv, double fv, double type, double guess) {
//FROM MS http://office.microsoft.com/en-us/excel-help/rate-HP005209232.aspx
int FINANCIAL_MAX_ITERATIONS = 20;//Bet accuracy with 128
double FINANCIAL_PRECISION = 0.0000001;//1.0e-8
double y, y0, y1, x0, x1 = 0, f = 0, i = 0;
double rate = guess;
if (Math.abs(rate) < FINANCIAL_PRECISION) {
y = pv * (1 + nper * rate) + pmt * (1 + rate * type) * nper + fv;
} else {
f = Math.exp(nper * Math.log(1 + rate));
y = pv * f + pmt * (1 / rate + type) * (f - 1) + fv;
}
y0 = pv + pmt * nper + fv;
y1 = pv * f + pmt * (1 / rate + type) * (f - 1) + fv;
// find root by Newton secant method
i = x0 = 0.0;
x1 = rate;
while ((Math.abs(y0 - y1) > FINANCIAL_PRECISION) && (i < FINANCIAL_MAX_ITERATIONS)) {
rate = (y1 * x0 - y0 * x1) / (y1 - y0);
x0 = x1;
x1 = rate;
if (Math.abs(rate) < FINANCIAL_PRECISION) {
y = pv * (1 + nper * rate) + pmt * (1 + rate * type) * nper + fv;
} else {
f = Math.exp(nper * Math.log(1 + rate));
y = pv * f + pmt * (1 / rate + type) * (f - 1) + fv;
}
y0 = y1;
y1 = y;
++i;
}
return rate;
}
/**
* Excel does not support infinities and NaNs, rather, it gives a #NUM! error in these cases
*
* @throws EvaluationException (#NUM!) if <tt>result</tt> is <tt>NaN</> or <tt>Infinity</tt>
*/
static final void checkValue(double result) throws EvaluationException {
if (Double.isNaN(result) || Double.isInfinite(result)) {
throw new EvaluationException(ErrorEval.NUM_ERROR);
}
}
}