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 "PotentialRegressionCurveCalculator.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 
PotentialRegressionCurveCalculator()41 PotentialRegressionCurveCalculator::PotentialRegressionCurveCalculator() :
42         m_fSlope( 0.0 ),
43         m_fIntercept( 0.0 )
44 {
45     ::rtl::math::setNan( & m_fSlope );
46     ::rtl::math::setNan( & m_fIntercept );
47 }
48 
~PotentialRegressionCurveCalculator()49 PotentialRegressionCurveCalculator::~PotentialRegressionCurveCalculator()
50 {}
51 
52 // ____ XRegressionCurveCalculator ____
recalculateRegression(const uno::Sequence<double> & aXValues,const uno::Sequence<double> & aYValues)53 void SAL_CALL PotentialRegressionCurveCalculator::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::isValidAndBothPositive()));
62 
63     const size_t nMax = aValues.first.size();
64     if( nMax == 0 )
65     {
66         ::rtl::math::setNan( & m_fSlope );
67         ::rtl::math::setNan( & m_fIntercept );
68         ::rtl::math::setNan( & m_fCorrelationCoeffitient );
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 += log( 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 = log( 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_fSlope = fQxy / fQx;
96     m_fIntercept = fAverageY - m_fSlope * fAverageX;
97     m_fCorrelationCoeffitient = fQxy / sqrt( fQx * fQy );
98 
99     m_fIntercept = exp( m_fIntercept );
100 }
101 
getCurveValue(double x)102 double SAL_CALL PotentialRegressionCurveCalculator::getCurveValue( double x )
103     throw (lang::IllegalArgumentException,
104            uno::RuntimeException)
105 {
106     double fResult;
107     ::rtl::math::setNan( & fResult );
108 
109     if( ! ( ::rtl::math::isNan( m_fSlope ) ||
110             ::rtl::math::isNan( m_fIntercept )))
111     {
112         fResult = m_fIntercept * pow( x, m_fSlope );
113     }
114 
115     return fResult;
116 }
117 
getCurveValues(double min,double max,::sal_Int32 nPointCount,const uno::Reference<chart2::XScaling> & xScalingX,const uno::Reference<chart2::XScaling> & xScalingY,::sal_Bool bMaySkipPointsInCalculation)118 uno::Sequence< geometry::RealPoint2D > SAL_CALL PotentialRegressionCurveCalculator::getCurveValues(
119     double min, double max, ::sal_Int32 nPointCount,
120     const uno::Reference< chart2::XScaling >& xScalingX,
121     const uno::Reference< chart2::XScaling >& xScalingY,
122     ::sal_Bool bMaySkipPointsInCalculation )
123     throw (lang::IllegalArgumentException,
124            uno::RuntimeException)
125 {
126     if( bMaySkipPointsInCalculation &&
127         isLogarithmicScaling( xScalingX ) &&
128         isLogarithmicScaling( xScalingY ))
129     {
130         // optimize result
131         uno::Sequence< geometry::RealPoint2D > aResult( 2 );
132         aResult[0].X = min;
133         aResult[0].Y = this->getCurveValue( min );
134         aResult[1].X = max;
135         aResult[1].Y = this->getCurveValue( max );
136 
137         return aResult;
138     }
139     return RegressionCurveCalculator::getCurveValues( min, max, nPointCount, xScalingX, xScalingY, bMaySkipPointsInCalculation );
140 }
141 
ImplGetRepresentation(const uno::Reference<util::XNumberFormatter> & xNumFormatter,::sal_Int32 nNumberFormatKey) const142 OUString PotentialRegressionCurveCalculator::ImplGetRepresentation(
143     const uno::Reference< util::XNumberFormatter >& xNumFormatter,
144     ::sal_Int32 nNumberFormatKey ) const
145 {
146     OUStringBuffer aBuf( C2U( "f(x) = " ));
147 
148     if( m_fIntercept == 0.0 )
149     {
150         aBuf.append( sal_Unicode( '0' ));
151     }
152     else if( m_fSlope == 0.0 )
153     {
154         aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fIntercept ));
155     }
156     else
157     {
158         if( ! rtl::math::approxEqual( m_fIntercept, 1.0 ) )
159         {
160             aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fIntercept ));
161             aBuf.append( sal_Unicode( ' ' ));
162         }
163         if( m_fSlope != 0.0 )
164         {
165             aBuf.appendAscii( RTL_CONSTASCII_STRINGPARAM( "x^" ));
166             aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fSlope ));
167         }
168     }
169 
170     return aBuf.makeStringAndClear();
171 }
172 
173 } //  namespace chart
174