Adding upstream version 4:7.4.7.upstream/4%7.4.7upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 392 insertions, 0 deletions

diff --git a/chart2/source/tools/PolynomialRegressionCurveCalculator.cxx b/chart2/source/tools/PolynomialRegressionCurveCalculator.cxx
new file mode 100644
index 000000000..3d7f1c076
--- /dev/null
+++ b/chart2/source/tools/PolynomialRegressionCurveCalculator.cxx
@@ -0,0 +1,392 @@
+/* -*- 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 <PolynomialRegressionCurveCalculator.hxx>
+#include <RegressionCalculationHelper.hxx>
+
+#include <cmath>
+#include <limits>
+#include <rtl/math.hxx>
+#include <rtl/ustrbuf.hxx>
+
+#include <SpecialCharacters.hxx>
+
+using namespace com::sun::star;
+
+namespace chart
+{
+
+static double lcl_GetDotProduct(std::vector<double>& aVec1, std::vector<double>& aVec2)
+{
+    double fResult = 0.0;
+    assert(aVec1.size() == aVec2.size());
+    for (size_t i = 0; i < aVec1.size(); ++i)
+        fResult += aVec1[i] * aVec2[i];
+    return fResult;
+}
+
+PolynomialRegressionCurveCalculator::PolynomialRegressionCurveCalculator()
+{}
+
+PolynomialRegressionCurveCalculator::~PolynomialRegressionCurveCalculator()
+{}
+
+void PolynomialRegressionCurveCalculator::computeCorrelationCoefficient(
+    RegressionCalculationHelper::tDoubleVectorPair& rValues,
+    const sal_Int32 aNoValues,
+    double yAverage )
+{
+    double aSumError = 0.0;
+    double aSumTotal = 0.0;
+    double aSumYpred2 = 0.0;
+
+    for( sal_Int32 i = 0; i < aNoValues; i++ )
+    {
+        double xValue = rValues.first[i];
+        double yActual = rValues.second[i];
+        double yPredicted = getCurveValue( xValue );
+        aSumTotal += (yActual - yAverage) * (yActual - yAverage);
+        aSumError += (yActual - yPredicted) * (yActual - yPredicted);
+        if(mForceIntercept)
+            aSumYpred2 += (yPredicted - mInterceptValue) * (yPredicted - mInterceptValue);
+    }
+
+    double aRSquared = 0.0;
+    if(mForceIntercept)
+    {
+        if (auto const div = aSumError + aSumYpred2)
+        {
+            aRSquared = aSumYpred2 / div;
+        }
+    }
+    else if (aSumTotal != 0.0)
+    {
+        aRSquared = 1.0 - (aSumError / aSumTotal);
+    }
+
+    if (aRSquared > 0.0)
+        m_fCorrelationCoefficient = std::sqrt(aRSquared);
+    else
+        m_fCorrelationCoefficient = 0.0;
+}
+
+// ____ XRegressionCurveCalculator ____
+void SAL_CALL PolynomialRegressionCurveCalculator::recalculateRegression(
+    const uno::Sequence< double >& aXValues,
+    const uno::Sequence< double >& aYValues )
+{
+    m_fCorrelationCoefficient = std::numeric_limits<double>::quiet_NaN();
+
+    RegressionCalculationHelper::tDoubleVectorPair aValues(
+        RegressionCalculationHelper::cleanup( aXValues, aYValues, RegressionCalculationHelper::isValid()));
+
+    const sal_Int32 aNoValues = aValues.first.size();
+
+    const sal_Int32 aNoPowers = mForceIntercept ? mDegree : mDegree + 1;
+
+    mCoefficients.clear();
+    mCoefficients.resize(aNoPowers, 0.0);
+
+    double yAverage = 0.0;
+
+    std::vector<double> yVector;
+    yVector.resize(aNoValues, 0.0);
+
+    for(sal_Int32 i = 0; i < aNoValues; i++)
+    {
+        double yValue = aValues.second[i];
+        if (mForceIntercept)
+            yValue -= mInterceptValue;
+        yVector[i] = yValue;
+        yAverage += yValue;
+    }
+    if (aNoValues != 0)
+    {
+        yAverage /= aNoValues;
+    }
+
+    // Special case for single variable regression like in LINEST
+    // implementation in Calc.
+    if (mDegree == 1)
+    {
+        std::vector<double> xVector;
+        xVector.resize(aNoValues, 0.0);
+        double xAverage = 0.0;
+
+        for(sal_Int32 i = 0; i < aNoValues; ++i)
+        {
+            double xValue = aValues.first[i];
+            xVector[i] = xValue;
+            xAverage += xValue;
+        }
+        if (aNoValues != 0)
+        {
+            xAverage /= aNoValues;
+        }
+
+        if (!mForceIntercept)
+        {
+            for (sal_Int32 i = 0; i < aNoValues; ++i)
+            {
+                xVector[i] -= xAverage;
+                yVector[i] -= yAverage;
+            }
+        }
+        double fSumXY = lcl_GetDotProduct(xVector, yVector);
+        double fSumX2 = lcl_GetDotProduct(xVector, xVector);
+
+        double fSlope = fSumXY / fSumX2;
+
+        if (!mForceIntercept)
+        {
+            mInterceptValue = ::rtl::math::approxSub(yAverage, fSlope * xAverage);
+            mCoefficients[0] = mInterceptValue;
+            mCoefficients[1] = fSlope;
+        }
+        else
+        {
+            mCoefficients[0] = fSlope;
+            mCoefficients.insert(mCoefficients.begin(), mInterceptValue);
+        }
+
+        computeCorrelationCoefficient(aValues, aNoValues, yAverage);
+        return;
+    }
+
+    std::vector<double> aQRTransposed;
+    aQRTransposed.resize(aNoValues * aNoPowers, 0.0);
+
+    for(sal_Int32 j = 0; j < aNoPowers; j++)
+    {
+        sal_Int32 aPower = mForceIntercept ? j+1 : j;
+        sal_Int32 aColumnIndex = j * aNoValues;
+        for(sal_Int32 i = 0; i < aNoValues; i++)
+        {
+            double xValue = aValues.first[i];
+            aQRTransposed[i + aColumnIndex] = std::pow(xValue, static_cast<int>(aPower));
+        }
+    }
+
+    // QR decomposition - based on org.apache.commons.math.linear.QRDecomposition from apache commons math (ASF)
+    sal_Int32 aMinorSize = std::min(aNoValues, aNoPowers);
+
+    std::vector<double> aDiagonal;
+    aDiagonal.resize(aMinorSize, 0.0);
+
+    // Calculate Householder reflectors
+    for (sal_Int32 aMinor = 0; aMinor < aMinorSize; aMinor++)
+    {
+        double aNormSqr = 0.0;
+        for (sal_Int32 x = aMinor; x < aNoValues; x++)
+        {
+            double c = aQRTransposed[x + aMinor * aNoValues];
+            aNormSqr += c * c;
+        }
+
+        double a;
+
+        if (aQRTransposed[aMinor + aMinor * aNoValues] > 0.0)
+            a = -std::sqrt(aNormSqr);
+        else
+            a = std::sqrt(aNormSqr);
+
+        aDiagonal[aMinor] = a;
+
+        if (a != 0.0)
+        {
+            aQRTransposed[aMinor + aMinor * aNoValues] -= a;
+
+            for (sal_Int32 aColumn = aMinor + 1; aColumn < aNoPowers; aColumn++)
+            {
+                double alpha = 0.0;
+                for (sal_Int32 aRow = aMinor; aRow < aNoValues; aRow++)
+                {
+                    alpha -= aQRTransposed[aRow + aColumn * aNoValues] * aQRTransposed[aRow + aMinor * aNoValues];
+                }
+                alpha /= a * aQRTransposed[aMinor + aMinor * aNoValues];
+
+                for (sal_Int32 aRow = aMinor; aRow < aNoValues; aRow++)
+                {
+                    aQRTransposed[aRow + aColumn * aNoValues] -= alpha * aQRTransposed[aRow + aMinor * aNoValues];
+                }
+            }
+        }
+    }
+
+    // Solve the linear equation
+    for (sal_Int32 aMinor = 0; aMinor < aMinorSize; aMinor++)
+    {
+        double aDotProduct = 0;
+
+        for (sal_Int32 aRow = aMinor; aRow < aNoValues; aRow++)
+        {
+            aDotProduct += yVector[aRow] * aQRTransposed[aRow + aMinor * aNoValues];
+        }
+        aDotProduct /= aDiagonal[aMinor] * aQRTransposed[aMinor + aMinor * aNoValues];
+
+        for (sal_Int32 aRow = aMinor; aRow < aNoValues; aRow++)
+        {
+            yVector[aRow] += aDotProduct * aQRTransposed[aRow + aMinor * aNoValues];
+        }
+
+    }
+
+    for (sal_Int32 aRow = aDiagonal.size() - 1; aRow >= 0; aRow--)
+    {
+        yVector[aRow] /= aDiagonal[aRow];
+        double yRow = yVector[aRow];
+        mCoefficients[aRow] = yRow;
+
+        for (sal_Int32 i = 0; i < aRow; i++)
+        {
+            yVector[i] -= yRow * aQRTransposed[i + aRow * aNoValues];
+        }
+    }
+
+    if(mForceIntercept)
+    {
+        mCoefficients.insert(mCoefficients.begin(), mInterceptValue);
+    }
+
+    // Calculate correlation coefficient
+    computeCorrelationCoefficient(aValues, aNoValues, yAverage);
+}
+
+double SAL_CALL PolynomialRegressionCurveCalculator::getCurveValue( double x )
+{
+    if (mCoefficients.empty())
+        return std::numeric_limits<double>::quiet_NaN();
+
+    sal_Int32 aNoCoefficients = static_cast<sal_Int32>(mCoefficients.size());
+
+    // Horner's method
+    double fResult = 0.0;
+    for (sal_Int32 i = aNoCoefficients - 1; i >= 0; i--)
+    {
+        fResult = mCoefficients[i] + (x * fResult);
+    }
+    return fResult;
+}
+
+OUString PolynomialRegressionCurveCalculator::ImplGetRepresentation(
+    const uno::Reference< util::XNumberFormatter >& xNumFormatter,
+    sal_Int32 nNumberFormatKey, sal_Int32* pFormulaMaxWidth /* = nullptr */ ) const
+{
+    OUStringBuffer aBuf( mYName + " = " );
+
+    sal_Int32 nValueLength=0;
+    sal_Int32 aLastIndex = mCoefficients.size() - 1;
+
+    if ( pFormulaMaxWidth && *pFormulaMaxWidth > 0 )
+    {
+        sal_Int32 nCharMin = aBuf.getLength(); // count characters different from coefficients
+        double nCoefficients = aLastIndex + 1.0; // number of coefficients
+        for (sal_Int32 i = aLastIndex; i >= 0; i--)
+        {
+            double aValue = mCoefficients[i];
+            if ( aValue == 0.0 )
+            { // do not count coefficient if it is 0
+                nCoefficients --;
+                continue;
+            }
+            if ( rtl::math::approxEqual( fabs( aValue ) , 1.0 ) )
+            { // do not count coefficient if it is 1
+                nCoefficients --;
+                if ( i == 0 ) // intercept = 1
+                    nCharMin ++;
+            }
+            if ( i != aLastIndex )
+                nCharMin += 3; // " + "
+            if ( i > 0 )
+            {
+                nCharMin += mXName.getLength() + 1; // " x"
+                if ( i > 1 )
+                    nCharMin +=1; // "^i"
+                if ( i >= 10 )
+                    nCharMin ++; // 2 digits for i
+            }
+        }
+        nValueLength = ( *pFormulaMaxWidth - nCharMin ) / nCoefficients;
+        if ( nValueLength <= 0 )
+            nValueLength = 1;
+    }
+
+    bool bFindValue = false;
+    sal_Int32 nLineLength = aBuf.getLength();
+    for (sal_Int32 i = aLastIndex; i >= 0; i--)
+    {
+        double aValue = mCoefficients[i];
+        OUStringBuffer aTmpBuf(""); // temporary buffer
+        if (aValue == 0.0)
+        {
+            continue;
+        }
+        else if (aValue < 0.0)
+        {
+            if ( bFindValue ) // if it is not the first aValue
+                aTmpBuf.append( " " );
+            aTmpBuf.append( OUStringChar(aMinusSign) + " ");
+            aValue = - aValue;
+        }
+        else
+        {
+            if ( bFindValue ) // if it is not the first aValue
+                aTmpBuf.append( " + " );
+        }
+        bFindValue = true;
+
+        // if nValueLength not calculated then nullptr
+        sal_Int32* pValueLength = nValueLength ? &nValueLength : nullptr;
+        OUString aValueString = getFormattedString( xNumFormatter, nNumberFormatKey, aValue, pValueLength );
+        if ( i == 0 || aValueString != "1" )  // aValueString may be rounded to 1 if nValueLength is small
+        {
+            aTmpBuf.append( aValueString );
+            if ( i > 0 ) // insert blank between coefficient and x
+                aTmpBuf.append( " " );
+        }
+
+        if(i > 0)
+        {
+            aTmpBuf.append( mXName );
+            if (i > 1)
+            {
+                if (i < 10) // simple case if only one digit
+                    aTmpBuf.append( aSuperscriptFigures[ i ] );
+                else
+                {
+                    OUString aValueOfi = OUString::number( i );
+                    for ( sal_Int32 n = 0; n < aValueOfi.getLength() ; n++ )
+                    {
+                        sal_Int32 nIndex = aValueOfi[n] - u'0';
+                        aTmpBuf.append( aSuperscriptFigures[ nIndex ] );
+                    }
+                }
+            }
+        }
+        addStringToEquation( aBuf, nLineLength, aTmpBuf, pFormulaMaxWidth );
+    }
+    if ( std::u16string_view(aBuf) == OUStringConcatenation( mYName + " = ") )
+        aBuf.append( "0" );
+
+    return aBuf.makeStringAndClear();
+}
+
+} //  namespace chart
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */