chart2/source/tools/ExponentialRegressionCurveCalculator.cxx

   1 /*************************************************************************
   2  *
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * Copyright 2000, 2010 Oracle and/or its affiliates.
   6  *
   7  * OpenOffice.org - a multi-platform office productivity suite
   8  *
   9  * This file is part of OpenOffice.org.
  10  *
  11  * OpenOffice.org is free software: you can redistribute it and/or modify
  12  * it under the terms of the GNU Lesser General Public License version 3
  13  * only, as published by the Free Software Foundation.
  14  *
  15  * OpenOffice.org is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU Lesser General Public License version 3 for more details
  19  * (a copy is included in the LICENSE file that accompanied this code).
  20  *
  21  * You should have received a copy of the GNU Lesser General Public License
  22  * version 3 along with OpenOffice.org.  If not, see
  23  * <http://www.openoffice.org/license.html>
  24  * for a copy of the LGPLv3 License.
  25  *
  26  ************************************************************************/
  27
  28 // MARKER(update_precomp.py): autogen include statement, do not remove
  29 #include "precompiled_chart2.hxx"
  30 #include "ExponentialRegressionCurveCalculator.hxx"
  31 #include "macros.hxx"
  32 #include "RegressionCalculationHelper.hxx"
  33
  34 #include <rtl/math.hxx>
  35 #include <rtl/ustrbuf.hxx>
  36
  37 using namespace ::com::sun::star;
  38
  39 using ::rtl::OUString;
  40 using ::rtl::OUStringBuffer;
  41
  42 namespace chart
  43 {
  44
  45 ExponentialRegressionCurveCalculator::ExponentialRegressionCurveCalculator() :
  46         m_fSlope( 0.0 ),
  47         m_fIntercept( 0.0 )
  48 {
  49     ::rtl::math::setNan( & m_fSlope );
  50     ::rtl::math::setNan( & m_fIntercept );
  51 }
  52
  53 ExponentialRegressionCurveCalculator::~ExponentialRegressionCurveCalculator()
  54 {}
  55
  56 // ____ XRegressionCurveCalculator ____
  57 void SAL_CALL ExponentialRegressionCurveCalculator::recalculateRegression(
  58     const uno::Sequence< double >& aXValues,
  59     const uno::Sequence< double >& aYValues )
  60     throw (uno::RuntimeException)
  61 {
  62     RegressionCalculationHelper::tDoubleVectorPair aValues(
  63         RegressionCalculationHelper::cleanup(
  64             aXValues, aYValues,
  65             RegressionCalculationHelper::isValidAndYPositive()));
  66
  67     const size_t nMax = aValues.first.size();
  68     if( nMax == 0 )
  69     {
  70         ::rtl::math::setNan( & m_fSlope );
  71         ::rtl::math::setNan( & m_fIntercept );
  72         ::rtl::math::setNan( & m_fCorrelationCoeffitient );
  73         return;
  74     }
  75
  76     double fAverageX = 0.0, fAverageY = 0.0;
  77     size_t i = 0;
  78     for( i = 0; i < nMax; ++i )
  79     {
  80         fAverageX += aValues.first[i];
  81         fAverageY += log( aValues.second[i] );
  82     }
  83
  84     const double fN = static_cast< double >( nMax );
  85     fAverageX /= fN;
  86     fAverageY /= fN;
  87
  88     double fQx = 0.0, fQy = 0.0, fQxy = 0.0;
  89     for( i = 0; i < nMax; ++i )
  90     {
  91         double fDeltaX = aValues.first[i] - fAverageX;
  92         double fDeltaY = log( aValues.second[i] ) - fAverageY;
  93
  94         fQx  += fDeltaX * fDeltaX;
  95         fQy  += fDeltaY * fDeltaY;
  96         fQxy += fDeltaX * fDeltaY;
  97     }
  98
  99     m_fSlope = fQxy / fQx;
 100     m_fIntercept = fAverageY - m_fSlope * fAverageX;
 101     m_fCorrelationCoeffitient = fQxy / sqrt( fQx * fQy );
 102
 103     m_fSlope = exp( m_fSlope );
 104     m_fIntercept = exp( m_fIntercept );
 105 }
 106
 107 double SAL_CALL ExponentialRegressionCurveCalculator::getCurveValue( double x )
 108     throw (lang::IllegalArgumentException,
 109            uno::RuntimeException)
 110 {
 111     double fResult;
 112     ::rtl::math::setNan( & fResult );
 113
 114     if( ! ( ::rtl::math::isNan( m_fSlope ) ||
 115             ::rtl::math::isNan( m_fIntercept )))
 116     {
 117         fResult = m_fIntercept * pow( m_fSlope, x );
 118     }
 119
 120     return fResult;
 121 }
 122
 123 uno::Sequence< geometry::RealPoint2D > SAL_CALL ExponentialRegressionCurveCalculator::getCurveValues(
 124     double min, double max, ::sal_Int32 nPointCount,
 125     const uno::Reference< chart2::XScaling >& xScalingX,
 126     const uno::Reference< chart2::XScaling >& xScalingY,
 127     ::sal_Bool bMaySkipPointsInCalculation )
 128     throw (lang::IllegalArgumentException,
 129            uno::RuntimeException)
 130 {
 131     if( bMaySkipPointsInCalculation &&
 132         isLinearScaling( xScalingX ) &&
 133         isLogarithmicScaling( xScalingY ))
 134     {
 135         // optimize result
 136         uno::Sequence< geometry::RealPoint2D > aResult( 2 );
 137         aResult[0].X = min;
 138         aResult[0].Y = this->getCurveValue( min );
 139         aResult[1].X = max;
 140         aResult[1].Y = this->getCurveValue( max );
 141
 142         return aResult;
 143     }
 144
 145     return RegressionCurveCalculator::getCurveValues( min, max, nPointCount, xScalingX, xScalingY, bMaySkipPointsInCalculation );
 146 }
 147
 148
 149 OUString ExponentialRegressionCurveCalculator::ImplGetRepresentation(
 150     const uno::Reference< util::XNumberFormatter >& xNumFormatter,
 151     ::sal_Int32 nNumberFormatKey ) const
 152 {
 153     OUStringBuffer aBuf( C2U( "f(x) = " ));
 154
 155     if( m_fIntercept == 0.0 ||
 156         m_fSlope == 0.0 )
 157     {
 158         aBuf.append( sal_Unicode( '0' ));
 159     }
 160     else if( rtl::math::approxEqual( m_fSlope, 1.0 ) )
 161     {
 162         aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fIntercept ));
 163     }
 164     else
 165     {
 166         if( ! rtl::math::approxEqual( m_fIntercept, 1.0 ) )
 167         {
 168             aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fIntercept ));
 169             aBuf.append( sal_Unicode( 0x00b7 ));
 170         }
 171
 172         if( m_fSlope < 0.0 )
 173             aBuf.append( sal_Unicode( '(' ));
 174         aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fSlope ));
 175         if( m_fSlope < 0.0 )
 176             aBuf.append( sal_Unicode( ')' ));
 177         aBuf.appendAscii( RTL_CONSTASCII_STRINGPARAM( "^x" ));
 178     }
 179
 180     return aBuf.makeStringAndClear();
 181 }
 182
 183 } //  namespace chart