繪製折線圖時,有時候數據需要做一些標記,如下圖所示效果,用到了 QCPItemTracer 類記錄備忘
void Storeplot::PlotSetTag(QCPGraph *Graph, double threshold, QVector<QCPItemTracer *> *TagVector)
{
QSharedPointer<QCPGraphDataContainer> tmpContainer;
tmpContainer = Graph->data();
int low = 0, high = tmpContainer->size();
double x,y;
qDebug("start TagVector.size()=%d", TagVector->size());
for(low = 0; low < high; low++)
{
y = (tmpContainer->constBegin() + low)->mainValue();
if(threshold < y)
{
QCPItemTracer *tempTracer = new QCPItemTracer(ui->plot);
tempTracer->setGraph(Graph);
tempTracer->setInterpolating(true);
tempTracer->setStyle(QCPItemTracer::tsCircle);
tempTracer->setPen(QPen(Qt::red));
tempTracer->setBrush(Qt::red);
tempTracer->setSize(7);
tempTracer->setGraphKey((tmpContainer->constBegin() + low)->mainKey());
TagVector->append(tempTracer);
//qDebug("i =%d y =%f %f", low, y, (tmpContainer->constBegin() + low)->mainKey());
}
}
qDebug("TagVector.size()=%d", TagVector->size());
qDebug("high =%d threshold=%f", high, threshold);
ui->plot->replot();
}
void Storeplot::PlotClearTag(QVector<QCPItemTracer *> *TagVector)
{
qDebug("PlotClearTag TagVector.size()=%d", TagVector->size());
for(int i = 0; i < TagVector->size(); i++)
{
QCPItemTracer *tempTracer = TagVector->at(i);
tempTracer->setGraph(0);
ui->plot->removeItem(tempTracer);
//delete tempTracer;
}
TagVector->clear();
qDebug("PlotClearTag TagVector.size()=%d", TagVector->size());
ui->plot->replot();
}