本文整理汇总了C++中QwtArray::clear方法的典型用法代码示例。如果您正苦于以下问题：C++ QwtArray::clear方法的具体用法？C++ QwtArray::clear怎么用？C++ QwtArray::clear使用的例子？那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类QwtArray的用法示例。
在下文中一共展示了QwtArray::clear方法的1个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C++代码示例。
示例1: drawHistogram
void QgsHistogramWidget::drawHistogram()
{
if ( !mVectorLayer || mSourceFieldExp.isEmpty() )
return;
QApplication::setOverrideCursor( Qt::WaitCursor );
if ( mValues.empty() )
{
bool ok;
mValues = mVectorLayer->getDoubleValues( mSourceFieldExp, ok );
if ( ! ok )
{
QApplication::restoreOverrideCursor();
return;
}
qSort( mValues.begin(), mValues.end() );
mHistogram.setValues( mValues );
mBinsSpinBox->blockSignals( true );
mBinsSpinBox->setValue( qMax( mHistogram.optimalNumberBins(), 30 ) );
mBinsSpinBox->blockSignals( false );
mStats.setStatistics( QgsStatisticalSummary::StDev );
mStats.calculate( mValues );
}
// clear plot
mpPlot->detachItems();
//ensure all children get removed
mpPlot->setAutoDelete( true );
// Set axis titles
mpPlot->setAxisTitle( QwtPlot::xBottom, QObject::tr( "Value" ) );
mpPlot->setAxisTitle( QwtPlot::yLeft, QObject::tr( "Count" ) );
mpPlot->setAxisAutoScale( QwtPlot::yLeft );
mpPlot->setAxisAutoScale( QwtPlot::xBottom );
// add a grid
QwtPlotGrid * grid = new QwtPlotGrid();
grid->enableX( false );
grid->setPen( mGridPen );
grid->attach( mpPlot );
// make colors list
mHistoColors.clear();
foreach ( QgsRendererRangeV2 range, mRanges )
{
mHistoColors << ( range.symbol() ? range.symbol()->color() : Qt::black );
}
//draw histogram
#if defined(QWT_VERSION) && QWT_VERSION>=0x060000
QwtPlotHistogram * plotHistogram = 0;
plotHistogram = createPlotHistogram( mRanges.count() > 0 ? mRanges.at( 0 ).label() : QString(),
mRanges.count() > 0 ? QBrush( mHistoColors.at( 0 ) ) : mBrush,
mRanges.count() > 0 ? Qt::NoPen : mPen );
#else
HistogramItem *plotHistogramItem = 0;
plotHistogramItem = createHistoItem( mRanges.count() > 0 ? mRanges.at( 0 ).label() : QString(),
mRanges.count() > 0 ? QBrush( mHistoColors.at( 0 ) ) : mBrush,
mRanges.count() > 0 ? Qt::NoPen : mPen );
#endif
#if defined(QWT_VERSION) && QWT_VERSION>=0x060000
QVector<QwtIntervalSample> dataHisto;
#else
// we safely assume that QT>=4.0 (min version is 4.7), therefore QwtArray is a QVector, so don't set size here
QwtArray<QwtDoubleInterval> intervalsHisto;
QwtArray<double> valuesHisto;
#endif
int bins = mBinsSpinBox->value();
QList<double> edges = mHistogram.binEdges( bins );
QList<int> counts = mHistogram.counts( bins );
int rangeIndex = 0;
int lastValue = 0;
for ( int bin = 0; bin < bins; ++bin )
{
int binValue = counts.at( bin );
//current bin crosses two graduated ranges, so we split between
//two histogram items
if ( rangeIndex < mRanges.count() - 1 && edges.at( bin ) > mRanges.at( rangeIndex ).upperValue() )
{
rangeIndex++;
#if defined(QWT_VERSION) && QWT_VERSION>=0x060000
plotHistogram->setSamples( dataHisto );
plotHistogram->attach( mpPlot );
plotHistogram = createPlotHistogram( mRanges.at( rangeIndex ).label(), mHistoColors.at( rangeIndex ) );
dataHisto.clear();
dataHisto << QwtIntervalSample( lastValue, mRanges.at( rangeIndex - 1 ).upperValue(), edges.at( bin ) );
#else
plotHistogramItem->setData( QwtIntervalData( intervalsHisto, valuesHisto ) );
plotHistogramItem->attach( mpPlot );
plotHistogramItem = createHistoItem( mRanges.at( rangeIndex ).label(), mHistoColors.at( rangeIndex ) );
//.........这里部分代码省略.........