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Diffstat (limited to 'chart2/source/tools/PotentialRegressionCurveCalculator.cxx')
| -rw-r--r-- | chart2/source/tools/PotentialRegressionCurveCalculator.cxx | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/chart2/source/tools/PotentialRegressionCurveCalculator.cxx b/chart2/source/tools/PotentialRegressionCurveCalculator.cxx new file mode 100644 index 000000000..eb054bd8d --- /dev/null +++ b/chart2/source/tools/PotentialRegressionCurveCalculator.cxx @@ -0,0 +1,195 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ +/* + * This file is part of the LibreOffice project. + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. + * + * This file incorporates work covered by the following license notice: + * + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed + * with this work for additional information regarding copyright + * ownership. The ASF licenses this file to you under the Apache + * License, Version 2.0 (the "License"); you may not use this file + * except in compliance with the License. You may obtain a copy of + * the License at http://www.apache.org/licenses/LICENSE-2.0 . + */ + +#include <PotentialRegressionCurveCalculator.hxx> +#include <RegressionCalculationHelper.hxx> +#include <SpecialCharacters.hxx> + +#include <rtl/math.hxx> +#include <rtl/ustrbuf.hxx> + +using namespace ::com::sun::star; + +namespace chart +{ + +PotentialRegressionCurveCalculator::PotentialRegressionCurveCalculator() + : m_fSlope(0.0) + , m_fIntercept(0.0) + , m_fSign(1.0) +{ + ::rtl::math::setNan( & m_fSlope ); + ::rtl::math::setNan( & m_fIntercept ); +} + +PotentialRegressionCurveCalculator::~PotentialRegressionCurveCalculator() +{} + +// ____ XRegressionCurveCalculator ____ +void SAL_CALL PotentialRegressionCurveCalculator::recalculateRegression( + const uno::Sequence< double >& aXValues, + const uno::Sequence< double >& aYValues ) +{ + RegressionCalculationHelper::tDoubleVectorPair aValues( + RegressionCalculationHelper::cleanup( + aXValues, aYValues, + RegressionCalculationHelper::isValidAndBothPositive())); + m_fSign = 1.0; + + size_t nMax = aValues.first.size(); + if( nMax <= 1 ) // at least 2 points + { + aValues = RegressionCalculationHelper::cleanup( + aXValues, aYValues, + RegressionCalculationHelper::isValidAndXPositiveAndYNegative()); + nMax = aValues.first.size(); + if( nMax <= 1 ) + { + ::rtl::math::setNan( & m_fSlope ); + ::rtl::math::setNan( & m_fIntercept ); + ::rtl::math::setNan( & m_fCorrelationCoefficient ); + return; + } + m_fSign = -1.0; + } + + double fAverageX = 0.0, fAverageY = 0.0; + size_t i = 0; + for( i = 0; i < nMax; ++i ) + { + fAverageX += log( aValues.first[i] ); + fAverageY += log( m_fSign * aValues.second[i] ); + } + + const double fN = static_cast< double >( nMax ); + fAverageX /= fN; + fAverageY /= fN; + + double fQx = 0.0, fQy = 0.0, fQxy = 0.0; + for( i = 0; i < nMax; ++i ) + { + double fDeltaX = log( aValues.first[i] ) - fAverageX; + double fDeltaY = log( m_fSign * aValues.second[i] ) - fAverageY; + + fQx += fDeltaX * fDeltaX; + fQy += fDeltaY * fDeltaY; + fQxy += fDeltaX * fDeltaY; + } + + m_fSlope = fQxy / fQx; + m_fIntercept = fAverageY - m_fSlope * fAverageX; + m_fCorrelationCoefficient = fQxy / sqrt( fQx * fQy ); + + m_fIntercept = m_fSign * exp( m_fIntercept ); +} + +double SAL_CALL PotentialRegressionCurveCalculator::getCurveValue( double x ) +{ + double fResult; + ::rtl::math::setNan( & fResult ); + + if( ! ( std::isnan( m_fSlope ) || + std::isnan( m_fIntercept ))) + { + fResult = m_fIntercept * pow( x, m_fSlope ); + } + + return fResult; +} + +uno::Sequence< geometry::RealPoint2D > SAL_CALL PotentialRegressionCurveCalculator::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 && + isLogarithmicScaling( xScalingX ) && + isLogarithmicScaling( xScalingY )) + { + // optimize result + uno::Sequence< geometry::RealPoint2D > aResult( 2 ); + aResult[0].X = min; + aResult[0].Y = getCurveValue( min ); + aResult[1].X = max; + aResult[1].Y = getCurveValue( max ); + + return aResult; + } + return RegressionCurveCalculator::getCurveValues( min, max, nPointCount, xScalingX, xScalingY, bMaySkipPointsInCalculation ); +} + +OUString PotentialRegressionCurveCalculator::ImplGetRepresentation( + const uno::Reference< util::XNumberFormatter >& xNumFormatter, + sal_Int32 nNumberFormatKey, sal_Int32* pFormulaMaxWidth /* = nullptr */ ) const +{ + bool bHasIntercept = !rtl::math::approxEqual( fabs(m_fIntercept), 1.0 ); + OUStringBuffer aBuf( mYName + " = " ); + sal_Int32 nLineLength = aBuf.getLength(); + sal_Int32 nValueLength=0; + if ( pFormulaMaxWidth && *pFormulaMaxWidth > 0 ) // count nValueLength + { + sal_Int32 nCharMin = nLineLength + mXName.getLength() + 3; // 3 = "^" + 2 extra characters + if ( m_fIntercept != 0.0 && m_fSlope != 0.0 ) + { + if ( m_fIntercept < 0.0 ) + nCharMin += 2; // "- " + if ( bHasIntercept ) + nValueLength = (*pFormulaMaxWidth - nCharMin) / 2; + } + if ( nValueLength == 0 ) // not yet calculated + nValueLength = *pFormulaMaxWidth - nCharMin; + if ( nValueLength <= 0 ) + nValueLength = 1; + } + + if( m_fIntercept == 0.0 ) + { + aBuf.append( '0' ); + } + else + { + // temporary buffer + OUStringBuffer aTmpBuf(""); + // if nValueLength not calculated then nullptr + sal_Int32* pValueLength = nValueLength ? &nValueLength : nullptr; + if ( m_fIntercept < 0.0 ) // add intercept value + aTmpBuf.append( OUStringChar(aMinusSign) ).append( " " ); + if( bHasIntercept ) + { + OUString aValueString = getFormattedString( xNumFormatter, nNumberFormatKey, fabs(m_fIntercept), pValueLength ); + if ( aValueString != "1" ) // aValueString may be rounded to 1 if nValueLength is small + { + aTmpBuf.append( aValueString ).append( " " ); + } + } + if( m_fSlope != 0.0 ) // add slope value + { + aTmpBuf.append( mXName ).append( "^" ); + aTmpBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fSlope, pValueLength )); + } + addStringToEquation( aBuf, nLineLength, aTmpBuf, pFormulaMaxWidth ); + } + + return aBuf.makeStringAndClear(); +} + +} // namespace chart + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |