Line data Source code
1 : /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
2 : /*
3 : * This file is part of the LibreOffice project.
4 : *
5 : * This Source Code Form is subject to the terms of the Mozilla Public
6 : * License, v. 2.0. If a copy of the MPL was not distributed with this
7 : * file, You can obtain one at http://mozilla.org/MPL/2.0/.
8 : *
9 : * This file incorporates work covered by the following license notice:
10 : *
11 : * Licensed to the Apache Software Foundation (ASF) under one or more
12 : * contributor license agreements. See the NOTICE file distributed
13 : * with this work for additional information regarding copyright
14 : * ownership. The ASF licenses this file to you under the Apache
15 : * License, Version 2.0 (the "License"); you may not use this file
16 : * except in compliance with the License. You may obtain a copy of
17 : * the License at http://www.apache.org/licenses/LICENSE-2.0 .
18 : */
19 :
20 : #include "ExponentialRegressionCurveCalculator.hxx"
21 : #include "macros.hxx"
22 : #include "RegressionCalculationHelper.hxx"
23 :
24 : #include <rtl/math.hxx>
25 : #include <rtl/ustrbuf.hxx>
26 :
27 : using namespace ::com::sun::star;
28 :
29 : using ::rtl::OUString;
30 : using ::rtl::OUStringBuffer;
31 :
32 : namespace chart
33 : {
34 :
35 0 : ExponentialRegressionCurveCalculator::ExponentialRegressionCurveCalculator() :
36 : m_fLogSlope( 0.0 ),
37 0 : m_fLogIntercept( 0.0 )
38 : {
39 0 : ::rtl::math::setNan( & m_fLogSlope );
40 0 : ::rtl::math::setNan( & m_fLogIntercept );
41 0 : }
42 :
43 0 : ExponentialRegressionCurveCalculator::~ExponentialRegressionCurveCalculator()
44 0 : {}
45 :
46 : // ____ XRegressionCurveCalculator ____
47 0 : void SAL_CALL ExponentialRegressionCurveCalculator::recalculateRegression(
48 : const uno::Sequence< double >& aXValues,
49 : const uno::Sequence< double >& aYValues )
50 : throw (uno::RuntimeException)
51 : {
52 : RegressionCalculationHelper::tDoubleVectorPair aValues(
53 : RegressionCalculationHelper::cleanup(
54 : aXValues, aYValues,
55 0 : RegressionCalculationHelper::isValidAndYPositive()));
56 :
57 0 : const size_t nMax = aValues.first.size();
58 0 : if( nMax == 0 )
59 : {
60 0 : ::rtl::math::setNan( & m_fLogSlope );
61 0 : ::rtl::math::setNan( & m_fLogIntercept );
62 0 : ::rtl::math::setNan( & m_fCorrelationCoeffitient );// actual it is coefficient of determination
63 0 : return;
64 : }
65 :
66 0 : double fAverageX = 0.0, fAverageY = 0.0;
67 0 : size_t i = 0;
68 0 : for( i = 0; i < nMax; ++i )
69 : {
70 0 : fAverageX += aValues.first[i];
71 0 : fAverageY += log( aValues.second[i] );
72 : }
73 :
74 0 : const double fN = static_cast< double >( nMax );
75 0 : fAverageX /= fN;
76 0 : fAverageY /= fN;
77 :
78 0 : double fQx = 0.0, fQy = 0.0, fQxy = 0.0;
79 0 : for( i = 0; i < nMax; ++i )
80 : {
81 0 : double fDeltaX = aValues.first[i] - fAverageX;
82 0 : double fDeltaY = log( aValues.second[i] ) - fAverageY;
83 :
84 0 : fQx += fDeltaX * fDeltaX;
85 0 : fQy += fDeltaY * fDeltaY;
86 0 : fQxy += fDeltaX * fDeltaY;
87 : }
88 :
89 0 : m_fLogSlope = fQxy / fQx;
90 0 : m_fLogIntercept = fAverageY - m_fLogSlope * fAverageX;
91 0 : m_fCorrelationCoeffitient = fQxy / sqrt( fQx * fQy );
92 :
93 : }
94 :
95 0 : double SAL_CALL ExponentialRegressionCurveCalculator::getCurveValue( double x )
96 : throw (lang::IllegalArgumentException,
97 : uno::RuntimeException)
98 : {
99 : double fResult;
100 0 : ::rtl::math::setNan( & fResult );
101 :
102 0 : if( ! ( ::rtl::math::isNan( m_fLogSlope ) ||
103 0 : ::rtl::math::isNan( m_fLogIntercept )))
104 : {
105 0 : fResult = exp(m_fLogIntercept + x * m_fLogSlope);
106 : }
107 :
108 0 : return fResult;
109 : }
110 :
111 0 : uno::Sequence< geometry::RealPoint2D > SAL_CALL ExponentialRegressionCurveCalculator::getCurveValues(
112 : double min, double max, ::sal_Int32 nPointCount,
113 : const uno::Reference< chart2::XScaling >& xScalingX,
114 : const uno::Reference< chart2::XScaling >& xScalingY,
115 : ::sal_Bool bMaySkipPointsInCalculation )
116 : throw (lang::IllegalArgumentException,
117 : uno::RuntimeException)
118 : {
119 0 : if( bMaySkipPointsInCalculation &&
120 0 : isLinearScaling( xScalingX ) &&
121 0 : isLogarithmicScaling( xScalingY ))
122 : {
123 : // optimize result
124 0 : uno::Sequence< geometry::RealPoint2D > aResult( 2 );
125 0 : aResult[0].X = min;
126 0 : aResult[0].Y = this->getCurveValue( min );
127 0 : aResult[1].X = max;
128 0 : aResult[1].Y = this->getCurveValue( max );
129 :
130 0 : return aResult;
131 : }
132 :
133 0 : return RegressionCurveCalculator::getCurveValues( min, max, nPointCount, xScalingX, xScalingY, bMaySkipPointsInCalculation );
134 : }
135 :
136 :
137 0 : OUString ExponentialRegressionCurveCalculator::ImplGetRepresentation(
138 : const uno::Reference< util::XNumberFormatter >& xNumFormatter,
139 : ::sal_Int32 nNumberFormatKey ) const
140 : {
141 0 : double fIntercept = exp(m_fLogIntercept);
142 0 : double fSlope = exp(m_fLogSlope);
143 0 : bool bHasSlope = !rtl::math::approxEqual( fSlope, 1.0 );
144 0 : bool bHasIntercept = !rtl::math::approxEqual( fIntercept, 1.0 );
145 :
146 0 : OUStringBuffer aBuf( C2U( "f(x) = " ));
147 :
148 0 : if ( fIntercept == 0.0)
149 : {
150 : // underflow, a true zero is impossible
151 0 : aBuf.append( C2U( "exp( " ));
152 0 : aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fLogIntercept) );
153 0 : aBuf.append( (m_fLogSlope < 0.0) ? C2U( " - " ) : C2U( " + " ));
154 0 : aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, fabs(m_fLogSlope)) );
155 0 : aBuf.append( C2U( " x )" ));
156 : }
157 : else
158 : {
159 0 : if (bHasIntercept)
160 : {
161 0 : aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, fIntercept) );
162 0 : aBuf.append( C2U( " exp( " ));
163 0 : aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fLogSlope) );
164 0 : aBuf.append( C2U( " x )" ));
165 : }
166 : else
167 : {
168 : // show logarithmic output, if intercept and slope both are near one
169 : // otherwise drop output of intercept, which is 1 here
170 0 : aBuf.append( C2U( " exp( " ));
171 0 : if (!bHasSlope)
172 : {
173 0 : aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fLogIntercept) );
174 0 : aBuf.append( (m_fLogSlope < 0.0) ? C2U( " - " ) : C2U( " + " ));
175 0 : aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, fabs(m_fLogSlope)) );
176 : }
177 : else
178 : {
179 0 : aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fLogSlope) );
180 : }
181 0 : aBuf.append( C2U( " x )" ));
182 : }
183 : }
184 :
185 0 : return aBuf.makeStringAndClear();
186 : }
187 :
188 : } // namespace chart
189 :
190 : /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
|
