chart2/source/tools/LogarithmicRegressionCurveCalculator.cxx

   1 /*************************************************************************
   2  *
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * Copyright 2008 by Sun Microsystems, Inc.
   6  *
   7  * OpenOffice.org - a multi-platform office productivity suite
   8  *
   9  * $RCSfile: LogarithmicRegressionCurveCalculator.cxx,v $
  10  * $Revision: 1.9 $
  11  *
  12  * This file is part of OpenOffice.org.
  13  *
  14  * OpenOffice.org is free software: you can redistribute it and/or modify
  15  * it under the terms of the GNU Lesser General Public License version 3
  16  * only, as published by the Free Software Foundation.
  17  *
  18  * OpenOffice.org is distributed in the hope that it will be useful,
  19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  * GNU Lesser General Public License version 3 for more details
  22  * (a copy is included in the LICENSE file that accompanied this code).
  23  *
  24  * You should have received a copy of the GNU Lesser General Public License
  25  * version 3 along with OpenOffice.org.  If not, see
  26  * <http://www.openoffice.org/license.html>
  27  * for a copy of the LGPLv3 License.
  28  *
  29  ************************************************************************/
  30
  31 // MARKER(update_precomp.py): autogen include statement, do not remove
  32 #include "precompiled_chart2.hxx"
  33 #include "LogarithmicRegressionCurveCalculator.hxx"
  34 #include "macros.hxx"
  35 #include "RegressionCalculationHelper.hxx"
  36
  37 #include <rtl/math.hxx>
  38 #include <rtl/ustrbuf.hxx>
  39
  40 using namespace ::com::sun::star;
  41
  42 using ::rtl::OUString;
  43 using ::rtl::OUStringBuffer;
  44
  45 namespace chart
  46 {
  47
  48 LogarithmicRegressionCurveCalculator::LogarithmicRegressionCurveCalculator() :
  49         m_fSlope( 0.0 ),
  50         m_fIntercept( 0.0 )
  51 {
  52     ::rtl::math::setNan( & m_fSlope );
  53     ::rtl::math::setNan( & m_fIntercept );
  54 }
  55
  56 LogarithmicRegressionCurveCalculator::~LogarithmicRegressionCurveCalculator()
  57 {}
  58
  59 // ____ XRegressionCurve ____
  60 void SAL_CALL LogarithmicRegressionCurveCalculator::recalculateRegression(
  61     const uno::Sequence< double >& aXValues,
  62     const uno::Sequence< double >& aYValues )
  63     throw (uno::RuntimeException)
  64 {
  65     RegressionCalculationHelper::tDoubleVectorPair aValues(
  66         RegressionCalculationHelper::cleanup(
  67             aXValues, aYValues,
  68             RegressionCalculationHelper::isValidAndXPositive()));
  69
  70     const size_t nMax = aValues.first.size();
  71     if( nMax == 0 )
  72     {
  73         ::rtl::math::setNan( & m_fSlope );
  74         ::rtl::math::setNan( & m_fIntercept );
  75         ::rtl::math::setNan( & m_fCorrelationCoeffitient );
  76         return;
  77     }
  78
  79     double fAverageX = 0.0, fAverageY = 0.0;
  80     size_t i = 0;
  81     for( i = 0; i < nMax; ++i )
  82     {
  83         fAverageX += log( aValues.first[i] );
  84         fAverageY += aValues.second[i];
  85     }
  86
  87     const double fN = static_cast< double >( nMax );
  88     fAverageX /= fN;
  89     fAverageY /= fN;
  90
  91     double fQx = 0.0, fQy = 0.0, fQxy = 0.0;
  92     for( i = 0; i < nMax; ++i )
  93     {
  94         double fDeltaX = log( aValues.first[i] ) - fAverageX;
  95         double fDeltaY = aValues.second[i] - fAverageY;
  96
  97         fQx  += fDeltaX * fDeltaX;
  98         fQy  += fDeltaY * fDeltaY;
  99         fQxy += fDeltaX * fDeltaY;
 100     }
 101
 102     m_fSlope = fQxy / fQx;
 103     m_fIntercept = fAverageY - m_fSlope * fAverageX;
 104     m_fCorrelationCoeffitient = fQxy / sqrt( fQx * fQy );
 105 }
 106
 107 double SAL_CALL LogarithmicRegressionCurveCalculator::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_fSlope * log( x ) + m_fIntercept;
 118     }
 119
 120     return fResult;
 121 }
 122
 123 uno::Sequence< geometry::RealPoint2D > SAL_CALL LogarithmicRegressionCurveCalculator::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         isLogarithmicScaling( xScalingX ) &&
 133         isLinearScaling( 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     return RegressionCurveCalculator::getCurveValues( min, max, nPointCount, xScalingX, xScalingY, bMaySkipPointsInCalculation );
 145 }
 146
 147 OUString LogarithmicRegressionCurveCalculator::ImplGetRepresentation(
 148     const uno::Reference< util::XNumberFormatter >& xNumFormatter,
 149     ::sal_Int32 nNumberFormatKey ) const
 150 {
 151     OUStringBuffer aBuf( C2U( "f(x) = " ));
 152
 153     bool bHaveSlope = false;
 154
 155     if( m_fSlope != 0.0 )
 156     {
 157         if( ::rtl::math::approxEqual( fabs( m_fSlope ), 1.0 ))
 158         {
 159             if( m_fSlope < 0 )
 160                 aBuf.append( UC_MINUS_SIGN );
 161         }
 162         else
 163         {
 164             aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fSlope ));
 165             aBuf.append( UC_SPACE );
 166         }
 167         aBuf.appendAscii( RTL_CONSTASCII_STRINGPARAM( "ln(x)" ));
 168         bHaveSlope = true;
 169     }
 170
 171     if( bHaveSlope )
 172     {
 173         if( m_fIntercept < 0.0 )
 174         {
 175             aBuf.append( UC_SPACE );
 176             aBuf.append( UC_MINUS_SIGN );
 177             aBuf.append( UC_SPACE );
 178             aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, fabs( m_fIntercept )));
 179         }
 180         else if( m_fIntercept > 0.0 )
 181         {
 182             aBuf.appendAscii( RTL_CONSTASCII_STRINGPARAM( " + " ));
 183             aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fIntercept ));
 184         }
 185     }
 186     else
 187     {
 188         aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fIntercept ));
 189     }
 190
 191     return aBuf.makeStringAndClear();
 192 }
 193
 194 } //  namespace chart