chart2/source/tools/LinearRegressionCurveCalculator.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: LinearRegressionCurveCalculator.cxx,v $
  10  * $Revision: 1.8 $
  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 "LinearRegressionCurveCalculator.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 LinearRegressionCurveCalculator::LinearRegressionCurveCalculator() :
  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 LinearRegressionCurveCalculator::~LinearRegressionCurveCalculator()
  57 {}
  58
  59 // ____ XRegressionCurveCalculator ____
  60 void SAL_CALL LinearRegressionCurveCalculator::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::isValid()));
  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     const double fN = static_cast< double >( nMax );
  80     double fSumX = 0.0, fSumY = 0.0, fSumXSq = 0.0, fSumYSq = 0.0, fSumXY = 0.0;
  81     for( size_t i = 0; i < nMax; ++i )
  82     {
  83         fSumX   += aValues.first[i];
  84         fSumY   += aValues.second[i];
  85         fSumXSq += aValues.first[i]  * aValues.first[i];
  86         fSumYSq += aValues.second[i] * aValues.second[i];
  87         fSumXY  += aValues.first[i]  * aValues.second[i];
  88     }
  89
  90     m_fSlope = (fN * fSumXY - fSumX * fSumY) / ( fN * fSumXSq - fSumX * fSumX );
  91     m_fIntercept = (fSumY - m_fSlope * fSumX) / fN;
  92
  93     m_fCorrelationCoeffitient = ( fN * fSumXY - fSumX * fSumY ) /
  94         sqrt( ( fN * fSumXSq - fSumX * fSumX ) *
  95               ( fN * fSumYSq - fSumY * fSumY ) );
  96 }
  97
  98 double SAL_CALL LinearRegressionCurveCalculator::getCurveValue( double x )
  99     throw (lang::IllegalArgumentException,
 100            uno::RuntimeException)
 101 {
 102     double fResult;
 103     ::rtl::math::setNan( & fResult );
 104
 105     if( ! ( ::rtl::math::isNan( m_fSlope ) ||
 106             ::rtl::math::isNan( m_fIntercept )))
 107     {
 108         fResult = m_fSlope * x + m_fIntercept;
 109     }
 110
 111     return fResult;
 112 }
 113
 114 uno::Sequence< geometry::RealPoint2D > SAL_CALL LinearRegressionCurveCalculator::getCurveValues(
 115     double min, double max, ::sal_Int32 nPointCount,
 116     const uno::Reference< chart2::XScaling >& xScalingX,
 117     const uno::Reference< chart2::XScaling >& xScalingY,
 118     ::sal_Bool bMaySkipPointsInCalculation )
 119     throw (lang::IllegalArgumentException,
 120            uno::RuntimeException)
 121 {
 122     if( bMaySkipPointsInCalculation &&
 123         isLinearScaling( xScalingX ) &&
 124         isLinearScaling( xScalingY ))
 125     {
 126         // optimize result
 127         uno::Sequence< geometry::RealPoint2D > aResult( 2 );
 128         aResult[0].X = min;
 129         aResult[0].Y = this->getCurveValue( min );
 130         aResult[1].X = max;
 131         aResult[1].Y = this->getCurveValue( max );
 132
 133         return aResult;
 134     }
 135     return RegressionCurveCalculator::getCurveValues( min, max, nPointCount, xScalingX, xScalingY, bMaySkipPointsInCalculation );
 136 }
 137
 138 OUString LinearRegressionCurveCalculator::ImplGetRepresentation(
 139     const uno::Reference< util::XNumberFormatter >& xNumFormatter,
 140     ::sal_Int32 nNumberFormatKey ) const
 141 {
 142     OUStringBuffer aBuf( C2U( "f(x) = " ));
 143
 144     bool bHaveSlope = false;
 145
 146     if( m_fSlope != 0.0 )
 147     {
 148         if( ::rtl::math::approxEqual( fabs( m_fSlope ), 1.0 ))
 149         {
 150             if( m_fSlope < 0 )
 151                 aBuf.append( UC_MINUS_SIGN );
 152         }
 153         else
 154             aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fSlope ));
 155         aBuf.append( sal_Unicode( 'x' ));
 156         bHaveSlope = true;
 157     }
 158
 159     if( bHaveSlope )
 160     {
 161         if( m_fIntercept < 0.0 )
 162         {
 163             aBuf.append( UC_SPACE );
 164             aBuf.append( UC_MINUS_SIGN );
 165             aBuf.append( UC_SPACE );
 166             aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, fabs( m_fIntercept )));
 167         }
 168         else if( m_fIntercept > 0.0 )
 169         {
 170             aBuf.appendAscii( RTL_CONSTASCII_STRINGPARAM( " + " ));
 171             aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fIntercept ));
 172         }
 173     }
 174     else
 175     {
 176         aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fIntercept ));
 177     }
 178
 179     return aBuf.makeStringAndClear();
 180 }
 181
 182 } //  namespace chart