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27 
28 // MARKER(update_precomp.py): autogen include statement, do not remove
29 #include "precompiled_chart2.hxx"
30 #include "LinearRegressionCurveCalculator.hxx"
31 #include "macros.hxx"
32 #include "RegressionCalculationHelper.hxx"
33 
34 #include <rtl/math.hxx>
35 #include <rtl/ustrbuf.hxx>
36 
37 using namespace ::com::sun::star;
38 
39 using ::rtl::OUString;
40 using ::rtl::OUStringBuffer;
41 
42 namespace chart
43 {
44 
45 LinearRegressionCurveCalculator::LinearRegressionCurveCalculator() :
46         m_fSlope( 0.0 ),
47         m_fIntercept( 0.0 )
48 {
49     ::rtl::math::setNan( & m_fSlope );
50     ::rtl::math::setNan( & m_fIntercept );
51 }
52 
53 LinearRegressionCurveCalculator::~LinearRegressionCurveCalculator()
54 {}
55 
56 // ____ XRegressionCurveCalculator ____
57 void SAL_CALL LinearRegressionCurveCalculator::recalculateRegression(
58     const uno::Sequence< double >& aXValues,
59     const uno::Sequence< double >& aYValues )
60     throw (uno::RuntimeException)
61 {
62     RegressionCalculationHelper::tDoubleVectorPair aValues(
63         RegressionCalculationHelper::cleanup(
64             aXValues, aYValues,
65             RegressionCalculationHelper::isValid()));
66 
67     const size_t nMax = aValues.first.size();
68     if( nMax == 0 )
69     {
70         ::rtl::math::setNan( & m_fSlope );
71         ::rtl::math::setNan( & m_fIntercept );
72         ::rtl::math::setNan( & m_fCorrelationCoeffitient );
73         return;
74     }
75 
76     const double fN = static_cast< double >( nMax );
77     double fSumX = 0.0, fSumY = 0.0, fSumXSq = 0.0, fSumYSq = 0.0, fSumXY = 0.0;
78     for( size_t i = 0; i < nMax; ++i )
79     {
80         fSumX   += aValues.first[i];
81         fSumY   += aValues.second[i];
82         fSumXSq += aValues.first[i]  * aValues.first[i];
83         fSumYSq += aValues.second[i] * aValues.second[i];
84         fSumXY  += aValues.first[i]  * aValues.second[i];
85     }
86 
87     m_fSlope = (fN * fSumXY - fSumX * fSumY) / ( fN * fSumXSq - fSumX * fSumX );
88     m_fIntercept = (fSumY - m_fSlope * fSumX) / fN;
89 
90     m_fCorrelationCoeffitient = ( fN * fSumXY - fSumX * fSumY ) /
91         sqrt( ( fN * fSumXSq - fSumX * fSumX ) *
92               ( fN * fSumYSq - fSumY * fSumY ) );
93 }
94 
95 double SAL_CALL LinearRegressionCurveCalculator::getCurveValue( double x )
96     throw (lang::IllegalArgumentException,
97            uno::RuntimeException)
98 {
99     double fResult;
100     ::rtl::math::setNan( & fResult );
101 
102     if( ! ( ::rtl::math::isNan( m_fSlope ) ||
103             ::rtl::math::isNan( m_fIntercept )))
104     {
105         fResult = m_fSlope * x + m_fIntercept;
106     }
107 
108     return fResult;
109 }
110 
111 uno::Sequence< geometry::RealPoint2D > SAL_CALL LinearRegressionCurveCalculator::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     if( bMaySkipPointsInCalculation &&
120         isLinearScaling( xScalingX ) &&
121         isLinearScaling( xScalingY ))
122     {
123         // optimize result
124         uno::Sequence< geometry::RealPoint2D > aResult( 2 );
125         aResult[0].X = min;
126         aResult[0].Y = this->getCurveValue( min );
127         aResult[1].X = max;
128         aResult[1].Y = this->getCurveValue( max );
129 
130         return aResult;
131     }
132     return RegressionCurveCalculator::getCurveValues( min, max, nPointCount, xScalingX, xScalingY, bMaySkipPointsInCalculation );
133 }
134 
135 OUString LinearRegressionCurveCalculator::ImplGetRepresentation(
136     const uno::Reference< util::XNumberFormatter >& xNumFormatter,
137     ::sal_Int32 nNumberFormatKey ) const
138 {
139     OUStringBuffer aBuf( C2U( "f(x) = " ));
140 
141     bool bHaveSlope = false;
142 
143     if( m_fSlope != 0.0 )
144     {
145         if( ::rtl::math::approxEqual( fabs( m_fSlope ), 1.0 ))
146         {
147             if( m_fSlope < 0 )
148                 aBuf.append( UC_MINUS_SIGN );
149         }
150         else
151             aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fSlope ));
152         aBuf.append( sal_Unicode( 'x' ));
153         bHaveSlope = true;
154     }
155 
156     if( bHaveSlope )
157     {
158         if( m_fIntercept < 0.0 )
159         {
160             aBuf.append( UC_SPACE );
161             aBuf.append( UC_MINUS_SIGN );
162             aBuf.append( UC_SPACE );
163             aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, fabs( m_fIntercept )));
164         }
165         else if( m_fIntercept > 0.0 )
166         {
167             aBuf.appendAscii( RTL_CONSTASCII_STRINGPARAM( " + " ));
168             aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fIntercept ));
169         }
170     }
171     else
172     {
173         aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fIntercept ));
174     }
175 
176     return aBuf.makeStringAndClear();
177 }
178 
179 } //  namespace chart
180