boxdatareader.cpp Example File

boxplotchart/boxdatareader.cpp
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 #include "boxdatareader.h"

 BoxDataReader::BoxDataReader(QIODevice *device) :
     QTextStream(device)
 {
 }

 void BoxDataReader::readFile(QIODevice *device)
 {
     QTextStream::setDevice(device);
 }

 QBoxSet *BoxDataReader::readBox()
 {
     QString line = readLine();
     if (line.startsWith("#"))
         return 0;

     QStringList strList = line.split(" ", QString::SkipEmptyParts);

     sortedList.clear();
     for (int i = 1; i < strList.count(); i++)
         sortedList.append(strList.at(i).toDouble());

     qSort(sortedList.begin(), sortedList.end());

     int count = sortedList.count();

     QBoxSet *box = new QBoxSet(strList.first());
     box->setValue(QBoxSet::LowerExtreme, sortedList.first());
     box->setValue(QBoxSet::UpperExtreme, sortedList.last());
     box->setValue(QBoxSet::Median, findMedian(0, count));
     box->setValue(QBoxSet::LowerQuartile, findMedian(0, count / 2));
     box->setValue(QBoxSet::UpperQuartile, findMedian(count / 2 + (count % 2), count));

     return box;
 }

 qreal BoxDataReader::findMedian(int begin, int end)
 {
     int count = end - begin;
     if (count % 2) {
         return sortedList.at(count / 2 + begin);
     } else {
         qreal right = sortedList.at(count / 2 + begin);
         qreal left = sortedList.at(count / 2 - 1 + begin);
         return (right + left) / 2.0;
     }
 }