chart2/source/tools/LinearRegressionCurveCalculator.cxx

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  27
  28 // MARKER(update_precomp.py): autogen include statement, do not remove
  29 #include "precompiled_chart2.hxx"
  30 #include "LinearRegressionCurveCalculator.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 LinearRegressionCurveCalculator::LinearRegressionCurveCalculator() :
  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 LinearRegressionCurveCalculator::~LinearRegressionCurveCalculator()
  54 {}
  55
  56 // ____ XRegressionCurveCalculator ____
  57 void SAL_CALL LinearRegressionCurveCalculator::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::isValid()));
  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     const double fN = static_cast< double >( nMax );
  77     double fSumX = 0.0, fSumY = 0.0, fSumXSq = 0.0, fSumYSq = 0.0, fSumXY = 0.0;
  78     for( size_t i = 0; i < nMax; ++i )
  79     {
  80         fSumX   += aValues.first[i];
  81         fSumY   += aValues.second[i];
  82         fSumXSq += aValues.first[i]  * aValues.first[i];
  83         fSumYSq += aValues.second[i] * aValues.second[i];
  84         fSumXY  += aValues.first[i]  * aValues.second[i];
  85     }
  86
  87     m_fSlope = (fN * fSumXY - fSumX * fSumY) / ( fN * fSumXSq - fSumX * fSumX );
  88     m_fIntercept = (fSumY - m_fSlope * fSumX) / fN;
  89
  90     m_fCorrelationCoeffitient = ( fN * fSumXY - fSumX * fSumY ) /
  91         sqrt( ( fN * fSumXSq - fSumX * fSumX ) *
  92               ( fN * fSumYSq - fSumY * fSumY ) );
  93 }
  94
  95 double SAL_CALL LinearRegressionCurveCalculator::getCurveValue( double x )
  96     throw (lang::IllegalArgumentException,
  97            uno::RuntimeException)
  98 {
  99     double fResult;
 100     ::rtl::math::setNan( & fResult );
 101
 102     if( ! ( ::rtl::math::isNan( m_fSlope ) ||
 103             ::rtl::math::isNan( m_fIntercept )))
 104     {
 105         fResult = m_fSlope * x + m_fIntercept;
 106     }
 107
 108     return fResult;
 109 }
 110
 111 uno::Sequence< geometry::RealPoint2D > SAL_CALL LinearRegressionCurveCalculator::getCurveValues(
 112     double min, double max, ::sal_Int32 nPointCount,
 113     const uno::Reference< chart2::XScaling >& xScalingX,
 114     const uno::Reference< chart2::XScaling >& xScalingY,
 115     ::sal_Bool bMaySkipPointsInCalculation )
 116     throw (lang::IllegalArgumentException,
 117            uno::RuntimeException)
 118 {
 119     if( bMaySkipPointsInCalculation &&
 120         isLinearScaling( xScalingX ) &&
 121         isLinearScaling( xScalingY ))
 122     {
 123         // optimize result
 124         uno::Sequence< geometry::RealPoint2D > aResult( 2 );
 125         aResult[0].X = min;
 126         aResult[0].Y = this->getCurveValue( min );
 127         aResult[1].X = max;
 128         aResult[1].Y = this->getCurveValue( max );
 129
 130         return aResult;
 131     }
 132     return RegressionCurveCalculator::getCurveValues( min, max, nPointCount, xScalingX, xScalingY, bMaySkipPointsInCalculation );
 133 }
 134
 135 OUString LinearRegressionCurveCalculator::ImplGetRepresentation(
 136     const uno::Reference< util::XNumberFormatter >& xNumFormatter,
 137     ::sal_Int32 nNumberFormatKey ) const
 138 {
 139     OUStringBuffer aBuf( C2U( "f(x) = " ));
 140
 141     bool bHaveSlope = false;
 142
 143     if( m_fSlope != 0.0 )
 144     {
 145         if( ::rtl::math::approxEqual( fabs( m_fSlope ), 1.0 ))
 146         {
 147             if( m_fSlope < 0 )
 148                 aBuf.append( UC_MINUS_SIGN );
 149         }
 150         else
 151             aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fSlope ));
 152         aBuf.append( sal_Unicode( 'x' ));
 153         bHaveSlope = true;
 154     }
 155
 156     if( bHaveSlope )
 157     {
 158         if( m_fIntercept < 0.0 )
 159         {
 160             aBuf.append( UC_SPACE );
 161             aBuf.append( UC_MINUS_SIGN );
 162             aBuf.append( UC_SPACE );
 163             aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, fabs( m_fIntercept )));
 164         }
 165         else if( m_fIntercept > 0.0 )
 166         {
 167             aBuf.appendAscii( RTL_CONSTASCII_STRINGPARAM( " + " ));
 168             aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fIntercept ));
 169         }
 170     }
 171     else
 172     {
 173         aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fIntercept ));
 174     }
 175
 176     return aBuf.makeStringAndClear();
 177 }
 178
 179 } //  namespace chart