diff options
| author | Laurent Balland-Poirier <laurent.balland-poirier@laposte.net> | 2015-09-30 17:46:37 +0200 |
|---|---|---|
| committer | Noel Grandin <noelgrandin@gmail.com> | 2015-10-07 06:42:06 +0000 |
| commit | 9ed8ec510cfa6b386628b6e2674040079f363d83 (patch) | |
| tree | f893c8e1765b9052fb1b80a4da50964315a977a5 /chart2 | |
| parent | ce9d48e5f58ec26e817202414a08225db1c11206 (diff) | |
Improve Power trend line equation
Skip intercept value if it is near 1
Change-Id: Ie52b2ac06c53c2e85b3c465be28081f6dc0ad2cb
Reviewed-on: https://gerrit.libreoffice.org/19038
Reviewed-by: Noel Grandin <noelgrandin@gmail.com>
Tested-by: Noel Grandin <noelgrandin@gmail.com>
Diffstat (limited to 'chart2')
| -rw-r--r-- | chart2/source/tools/PotentialRegressionCurveCalculator.cxx | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/chart2/source/tools/PotentialRegressionCurveCalculator.cxx b/chart2/source/tools/PotentialRegressionCurveCalculator.cxx index c8a4b267057d..1a9c2be98a14 100644 --- a/chart2/source/tools/PotentialRegressionCurveCalculator.cxx +++ b/chart2/source/tools/PotentialRegressionCurveCalculator.cxx @@ -54,13 +54,13 @@ void SAL_CALL PotentialRegressionCurveCalculator::recalculateRegression( m_fSign = 1.0; size_t nMax = aValues.first.size(); - if( nMax == 0 ) + if( nMax <= 1 ) // at least 2 points { aValues = RegressionCalculationHelper::cleanup( aXValues, aYValues, RegressionCalculationHelper::isValidAndXPositiveAndYNegative()); nMax = aValues.first.size(); - if( nMax == 0 ) + if( nMax <= 1 ) { ::rtl::math::setNan( & m_fSlope ); ::rtl::math::setNan( & m_fIntercept ); @@ -148,7 +148,7 @@ OUString PotentialRegressionCurveCalculator::ImplGetRepresentation( if( m_fIntercept == 0.0 ) { - aBuf.append( '0'); + aBuf.append( '0' ); } else if( m_fSlope == 0.0 ) { @@ -156,16 +156,18 @@ OUString PotentialRegressionCurveCalculator::ImplGetRepresentation( } else { - if( ! rtl::math::approxEqual( m_fIntercept, 1.0 ) ) + if( ! rtl::math::approxEqual( fabs(m_fIntercept), 1.0 ) ) { aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fIntercept )); aBuf.append( ' '); } - if( m_fSlope != 0.0 ) + else // skip intercept if its value is 1 (or near 1) { - aBuf.append( "x^" ); - aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fSlope )); + if ( m_fIntercept < 0.0 ) + aBuf.append( "- " ); } + aBuf.append( "x^" ); + aBuf.append( getFormattedString( xNumFormatter, nNumberFormatKey, m_fSlope )); } return aBuf.makeStringAndClear(); |