MeanValueRegressionCurveCalculator.cxx

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#include <MeanValueRegressionCurveCalculator.hxx>
 
#include <osl/diagnose.h>
 
#include <cmath>
#include <limits>
 
using namespace ::com::sun::star;
 
namespace chart
{
 
MeanValueRegressionCurveCalculator::MeanValueRegressionCurveCalculator() :
        m_fMeanValue( std::numeric_limits<double>::quiet_NaN() )
{
}
 
MeanValueRegressionCurveCalculator::~MeanValueRegressionCurveCalculator()
{}
 
// ____ XRegressionCurveCalculator ____
void SAL_CALL MeanValueRegressionCurveCalculator::recalculateRegression(
    const uno::Sequence< double >& /*aXValues*/,
    const uno::Sequence< double >& aYValues )
{
    const sal_Int32 nDataLength = aYValues.getLength();
    sal_Int32 nMax = nDataLength;
    double fSumY = 0.0;
    const double * pY = aYValues.getConstArray();
 
    for( sal_Int32 i = 0; i < nDataLength; ++i )
    {
        if( std::isnan( pY[i] ) ||
            std::isinf( pY[i] ))
            --nMax;
        else
            fSumY += pY[i];
    }
 
    m_fCorrelationCoefficient = 0.0;
 
    if( nMax == 0 )
    {
        m_fMeanValue = std::numeric_limits<double>::quiet_NaN();
    }
    else
    {
        m_fMeanValue = fSumY / static_cast< double >( nMax );
 
        // correlation coefficient: standard deviation
        if( nMax > 1 )
        {
            double fErrorSum = 0.0;
            for( sal_Int32 i = 0; i < nDataLength; ++i )
            {
                if( !std::isnan( pY[i] ) &&
                    !std::isinf( pY[i] ))
                {
                    double v = m_fMeanValue - pY[i];
                    fErrorSum += (v*v);
                }
            }
            OSL_ASSERT( fErrorSum >= 0.0 );
            m_fCorrelationCoefficient = sqrt( fErrorSum / (nMax - 1 ));
        }
    }
}
 
double SAL_CALL MeanValueRegressionCurveCalculator::getCurveValue( double /*x*/ )
{
    return m_fMeanValue;
}
 
uno::Sequence< geometry::RealPoint2D > SAL_CALL MeanValueRegressionCurveCalculator::getCurveValues(
    double min, double max, ::sal_Int32 nPointCount,
    const uno::Reference< chart2::XScaling >& xScalingX,
    const uno::Reference< chart2::XScaling >& xScalingY,
    sal_Bool bMaySkipPointsInCalculation )
{
    if( bMaySkipPointsInCalculation )
    {
        // optimize result
        uno::Sequence< geometry::RealPoint2D > aResult{ { min, m_fMeanValue },
                                                        { max, m_fMeanValue } };
 
        return aResult;
    }
    return RegressionCurveCalculator::getCurveValues( min, max, nPointCount, xScalingX, xScalingY, bMaySkipPointsInCalculation );
}
 
OUString MeanValueRegressionCurveCalculator::ImplGetRepresentation(
    const uno::Reference< util::XNumberFormatter >& xNumFormatter,
    sal_Int32 nNumberFormatKey, sal_Int32* pFormulaLength /* = nullptr */ ) const
{
    OUString aBuf(mYName + " = ");
    if ( pFormulaLength )
    {
        *pFormulaLength -= aBuf.getLength();
        if ( *pFormulaLength <= 0 )
            return "###";
    }
    return ( aBuf + getFormattedString( xNumFormatter, nNumberFormatKey, m_fMeanValue, pFormulaLength ) );
}
 
} //  namespace chart
 
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