1 /************************************************************** 2 * 3 * Licensed to the Apache Software Foundation (ASF) under one 4 * or more contributor license agreements. See the NOTICE file 5 * distributed with this work for additional information 6 * regarding copyright ownership. The ASF licenses this file 7 * to you under the Apache License, Version 2.0 (the 8 * "License"); you may not use this file except in compliance 9 * with the License. You may obtain a copy of the License at 10 * 11 * http://www.apache.org/licenses/LICENSE-2.0 12 * 13 * Unless required by applicable law or agreed to in writing, 14 * software distributed under the License is distributed on an 15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 16 * KIND, either express or implied. See the License for the 17 * specific language governing permissions and limitations 18 * under the License. 19 * 20 *************************************************************/ 21 22 23 24 // MARKER(update_precomp.py): autogen include statement, do not remove 25 #include "precompiled_chart2.hxx" 26 #include "ExponentialRegressionCurveCalculator.hxx" 27 #include "macros.hxx" 28 #include "RegressionCalculationHelper.hxx" 29 30 #include <rtl/math.hxx> 31 #include <rtl/ustrbuf.hxx> 32 33 using namespace ::com::sun::star; 34 35 using ::rtl::OUString; 36 using ::rtl::OUStringBuffer; 37 38 namespace chart 39 { 40 41 ExponentialRegressionCurveCalculator::ExponentialRegressionCurveCalculator() : 42 m_fLogSlope( 0.0 ), 43 m_fLogIntercept( 0.0 ) 44 { 45 ::rtl::math::setNan( & m_fLogSlope ); 46 ::rtl::math::setNan( & m_fLogIntercept ); 47 } 48 49 ExponentialRegressionCurveCalculator::~ExponentialRegressionCurveCalculator() 50 {} 51 52 // ____ XRegressionCurveCalculator ____ 53 void SAL_CALL ExponentialRegressionCurveCalculator::recalculateRegression( 54 const uno::Sequence< double >& aXValues, 55 const uno::Sequence< double >& aYValues ) 56 throw (uno::RuntimeException) 57 { 58 RegressionCalculationHelper::tDoubleVectorPair aValues( 59 RegressionCalculationHelper::cleanup( 60 aXValues, aYValues, 61 RegressionCalculationHelper::isValidAndYPositive())); 62 63 const size_t nMax = aValues.first.size(); 64 if( nMax == 0 ) 65 { 66 ::rtl::math::setNan( & m_fLogSlope ); 67 ::rtl::math::setNan( & m_fLogIntercept ); 68 ::rtl::math::setNan( & m_fCorrelationCoeffitient );// actual it is coefficient of determination 69 return; 70 } 71 72 double fAverageX = 0.0, fAverageY = 0.0; 73 size_t i = 0; 74 for( i = 0; i < nMax; ++i ) 75 { 76 fAverageX += aValues.first[i]; 77 fAverageY += log( aValues.second[i] ); 78 } 79 80 const double fN = static_cast< double >( nMax ); 81 fAverageX /= fN; 82 fAverageY /= fN; 83 84 double fQx = 0.0, fQy = 0.0, fQxy = 0.0; 85 for( i = 0; i < nMax; ++i ) 86 { 87 double fDeltaX = aValues.first[i] - fAverageX; 88 double fDeltaY = log( aValues.second[i] ) - fAverageY; 89 90 fQx += fDeltaX * fDeltaX; 91 fQy += fDeltaY * fDeltaY; 92 fQxy += fDeltaX * fDeltaY; 93 } 94 95 m_fLogSlope = fQxy / fQx; 96 m_fLogIntercept = fAverageY - m_fLogSlope * fAverageX; 97 m_fCorrelationCoeffitient = fQxy / sqrt( fQx * fQy ); 98 99 } 100 101 double SAL_CALL ExponentialRegressionCurveCalculator::getCurveValue( double x ) 102 throw (lang::IllegalArgumentException, 103 uno::RuntimeException) 104 { 105 double fResult; 106 ::rtl::math::setNan( & fResult ); 107 108 if( ! ( ::rtl::math::isNan( m_fLogSlope ) || 109 ::rtl::math::isNan( m_fLogIntercept ))) 110 { 111 fResult = exp(m_fLogIntercept + x * m_fLogSlope); 112 } 113 114 return fResult; 115 } 116 117 uno::Sequence< geometry::RealPoint2D > SAL_CALL ExponentialRegressionCurveCalculator::getCurveValues( 118 double min, double max, ::sal_Int32 nPointCount, 119 const uno::Reference< chart2::XScaling >& xScalingX, 120 const uno::Reference< chart2::XScaling >& xScalingY, 121 ::sal_Bool bMaySkipPointsInCalculation ) 122 throw (lang::IllegalArgumentException, 123 uno::RuntimeException) 124 { 125 if( bMaySkipPointsInCalculation && 126 isLinearScaling( xScalingX ) && 127 isLogarithmicScaling( xScalingY )) 128 { 129 // optimize result 130 uno::Sequence< geometry::RealPoint2D > aResult( 2 ); 131 aResult[0].X = min; 132 aResult[0].Y = this->getCurveValue( min ); 133 aResult[1].X = max; 134 aResult[1].Y = this->getCurveValue( max ); 135 136 return aResult; 137 } 138 139 return RegressionCurveCalculator::getCurveValues( min, max, nPointCount, xScalingX, xScalingY, bMaySkipPointsInCalculation ); 140 } 141 142 143 OUString ExponentialRegressionCurveCalculator::ImplGetRepresentation( 144 const uno::Reference< util::XNumberFormatter >& xNumFormatter, 145 ::sal_Int32 nNumberFormatKey ) const 146 { 147 double fIntercept = exp(m_fLogIntercept); 148 double fSlope = exp(m_fLogSlope); 149 bool bHasSlope = !rtl::math::approxEqual( fSlope, 1.0 ); 150 bool bHasIntercept = !rtl::math::approxEqual( fIntercept, 1.0 ); 151 152 OUStringBuffer aBuf( C2U( "f(x) = " )); 153 154 if ( fIntercept == 0.0) 155 { 156 // underflow, a true zero is impossible 157 aBuf.append( C2U( "exp( " )); 158 aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fLogIntercept) ); 159 aBuf.append( (m_fLogSlope < 0.0) ? C2U( " - " ) : C2U( " + " )); 160 aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, fabs(m_fLogSlope)) ); 161 aBuf.append( C2U( " x )" )); 162 } 163 else 164 { 165 if (bHasIntercept) 166 { 167 aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, fIntercept) ); 168 aBuf.append( C2U( " exp( " )); 169 aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fLogSlope) ); 170 aBuf.append( C2U( " x )" )); 171 } 172 else 173 { 174 // show logarithmic output, if intercept and slope both are near one 175 // otherwise drop output of intercept, which is 1 here 176 aBuf.append( C2U( " exp( " )); 177 if (!bHasSlope) 178 { 179 aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fLogIntercept) ); 180 aBuf.append( (m_fLogSlope < 0.0) ? C2U( " - " ) : C2U( " + " )); 181 aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, fabs(m_fLogSlope)) ); 182 } 183 else 184 { 185 aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fLogSlope) ); 186 } 187 aBuf.append( C2U( " x )" )); 188 } 189 } 190 191 return aBuf.makeStringAndClear(); 192 } 193 194 } // namespace chart 195