1 files changed, 201 insertions, 0 deletions
diff --git a/chart2/source/tools/ExponentialRegressionCurveCalculator.cxx b/chart2/source/tools/ExponentialRegressionCurveCalculator.cxx
new file mode 100644
index 000000000000..3bb08f27b1bd
--- /dev/null
+++ b/chart2/source/tools/ExponentialRegressionCurveCalculator.cxx
@@ -0,0 +1,201 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*************************************************************************
+ *
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * Copyright 2000, 2010 Oracle and/or its affiliates.
+ *
+ * OpenOffice.org - a multi-platform office productivity suite
+ *
+ * This file is part of OpenOffice.org.
+ *
+ * OpenOffice.org is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 3
+ * only, as published by the Free Software Foundation.
+ *
+ * OpenOffice.org is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License version 3 for more details
+ * (a copy is included in the LICENSE file that accompanied this code).
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * version 3 along with OpenOffice.org.  If not, see
+ * <http://www.openoffice.org/license.html>
+ * for a copy of the LGPLv3 License.
+ *
+ ************************************************************************/
+
+// MARKER(update_precomp.py): autogen include statement, do not remove
+#include "precompiled_chart2.hxx"
+#include "ExponentialRegressionCurveCalculator.hxx"
+#include "macros.hxx"
+#include "RegressionCalculationHelper.hxx"
+
+#include <rtl/math.hxx>
+#include <rtl/ustrbuf.hxx>
+
+using namespace ::com::sun::star;
+
+using ::rtl::OUString;
+using ::rtl::OUStringBuffer;
+
+namespace chart
+{
+
+ExponentialRegressionCurveCalculator::ExponentialRegressionCurveCalculator() :
+        m_fLogSlope( 0.0 ),
+        m_fLogIntercept( 0.0 )
+{
+    ::rtl::math::setNan( & m_fLogSlope );
+    ::rtl::math::setNan( & m_fLogIntercept );
+}
+
+ExponentialRegressionCurveCalculator::~ExponentialRegressionCurveCalculator()
+{}
+
+// ____ XRegressionCurveCalculator ____
+void SAL_CALL ExponentialRegressionCurveCalculator::recalculateRegression(
+    const uno::Sequence< double >& aXValues,
+    const uno::Sequence< double >& aYValues )
+    throw (uno::RuntimeException)
+{
+    RegressionCalculationHelper::tDoubleVectorPair aValues(
+        RegressionCalculationHelper::cleanup(
+            aXValues, aYValues,
+            RegressionCalculationHelper::isValidAndYPositive()));
+
+    const size_t nMax = aValues.first.size();
+    if( nMax == 0 )
+    {
+        ::rtl::math::setNan( & m_fLogSlope );
+        ::rtl::math::setNan( & m_fLogIntercept );
+        ::rtl::math::setNan( & m_fCorrelationCoeffitient );// actual it is coefficient of determination
+        return;
+    }
+
+    double fAverageX = 0.0, fAverageY = 0.0;
+    size_t i = 0;
+    for( i = 0; i < nMax; ++i )
+    {
+        fAverageX += aValues.first[i];
+        fAverageY += log( 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 = aValues.first[i] - fAverageX;
+        double fDeltaY = log( aValues.second[i] ) - fAverageY;
+
+        fQx  += fDeltaX * fDeltaX;
+        fQy  += fDeltaY * fDeltaY;
+        fQxy += fDeltaX * fDeltaY;
+    }
+
+    m_fLogSlope = fQxy / fQx;
+    m_fLogIntercept = fAverageY - m_fLogSlope * fAverageX;
+    m_fCorrelationCoeffitient = fQxy / sqrt( fQx * fQy );
+
+}
+
+double SAL_CALL ExponentialRegressionCurveCalculator::getCurveValue( double x )
+    throw (lang::IllegalArgumentException,
+           uno::RuntimeException)
+{
+    double fResult;
+    ::rtl::math::setNan( & fResult );
+
+    if( ! ( ::rtl::math::isNan( m_fLogSlope ) ||
+            ::rtl::math::isNan( m_fLogIntercept )))
+    {
+        fResult = exp(m_fLogIntercept + x * m_fLogSlope);
+    }
+
+    return fResult;
+}
+
+uno::Sequence< geometry::RealPoint2D > SAL_CALL ExponentialRegressionCurveCalculator::getCurveValues(
+    double min, double max, ::sal_Int32 nPointCount,
+    const uno::Reference< chart2::XScaling >& xScalingX,
+    const uno::Reference< chart2::XScaling >& xScalingY,
+    ::sal_Bool bMaySkipPointsInCalculation )
+    throw (lang::IllegalArgumentException,
+           uno::RuntimeException)
+{
+    if( bMaySkipPointsInCalculation &&
+        isLinearScaling( xScalingX ) &&
+        isLogarithmicScaling( xScalingY ))
+    {
+        // optimize result
+        uno::Sequence< geometry::RealPoint2D > aResult( 2 );
+        aResult[0].X = min;
+        aResult[0].Y = this->getCurveValue( min );
+        aResult[1].X = max;
+        aResult[1].Y = this->getCurveValue( max );
+
+        return aResult;
+    }
+
+    return RegressionCurveCalculator::getCurveValues( min, max, nPointCount, xScalingX, xScalingY, bMaySkipPointsInCalculation );
+}
+
+
+OUString ExponentialRegressionCurveCalculator::ImplGetRepresentation(
+    const uno::Reference< util::XNumberFormatter >& xNumFormatter,
+    ::sal_Int32 nNumberFormatKey ) const
+{
+    double fIntercept = exp(m_fLogIntercept);
+    double fSlope = exp(m_fLogSlope);
+    bool bHasSlope = !rtl::math::approxEqual( fSlope, 1.0 );
+    bool bHasIntercept = !rtl::math::approxEqual( fIntercept, 1.0 );
+
+    OUStringBuffer aBuf( C2U( "f(x) = " ));
+
+    if ( fIntercept == 0.0)
+    {
+        // underflow, a true zero is impossible
+        aBuf.append( C2U( "exp( " ));
+        aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fLogIntercept) );
+        aBuf.append( (m_fLogSlope < 0.0) ? C2U( " - " ) : C2U( " + " ));
+        aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, fabs(m_fLogSlope)) );
+        aBuf.append( C2U( " x )" ));
+    }
+    else
+    {
+        if (bHasIntercept)
+        {
+            aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, fIntercept) );
+            aBuf.append( C2U( " exp( " ));
+            aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fLogSlope) );
+            aBuf.append( C2U( " x )" ));
+        }
+        else
+        {
+            // show logarithmic output, if intercept and slope both are near one
+            // otherwise drop output of intercept, which is 1 here
+            aBuf.append( C2U( " exp( " ));
+            if (!bHasSlope)
+            {
+                aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fLogIntercept) );
+                aBuf.append( (m_fLogSlope < 0.0) ? C2U( " - " ) : C2U( " + " ));
+                aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, fabs(m_fLogSlope)) );
+            }
+            else
+            {
+                aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fLogSlope) );
+            }
+            aBuf.append( C2U( " x )" ));
+        }
+    }
+
+    return aBuf.makeStringAndClear();
+}
+
+} //  namespace chart
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */