Hi there,
Im trying to plot a heatmap from a root CERN TH2D histogram. I think my data is correct since it matches what I'm expecting. But when I try to display the result, my data points are not plotted where I'm expecting them; they are shifted.
To make it a little bit more clear, if I'm watching (x, y) = (104, 75), the result seems to be displayed at (104.5, 75.5)...
I ran the code in debug mode and the couple (x, y) from my data set is always (104, 75) as deep as I can go. So I feel the data is correctly transmitted.
Though, when I plot it, the lower left corner of this point appears at (104.5, 75.5)...
Here is a plot of the result : https://imgur.com/a/Higs8Ib
What I was expecting, is this little white square to be centered on (x, y) = (104, 75).
Thank you very much for your help.
Regards
Olivier
int plot_widget::plot_hit_map(
const std::vector<daq::mapping::coordinate_dxy>& coordinates, //
const QString& title, //
const QString& xlabel, //
const QString& ylabel)
{
zeros.clear();
plot->setInteractions(QCP::iSelectItems | QCP::iRangeDrag | QCP::iRangeZoom);
plot->xAxis->setLabel(xlabel);
plot->yAxis->setLabel(ylabel);
auto map = create_new_map();
map->colorScale()->setDataRange(QCPRange(0, 1));
// TH2::TH2(const char* name, const char* title, Int_t nbinsx, Double_t
// xlow, Double_t xup, Int_t nbinsy, Double_t ylow, Double_t yup);
auto heatmap =
std::make_unique<TH2C>("hm", title.toLatin1(), 128, 0, 127, 128, 0, 127);
map->data()->setRange(QCPRange(0, 127), QCPRange(0, 127));
for (auto& c : coordinates)
if (!(c.x == 0 && c.y == 0)) heatmap->Fill(c.x, c.y);
else
zeros.push_back(c);
int xc, yc;
for (int x{1}; x < 128; x++)
{
for (int y{1}; y < 128; y++)
{
Int_t data = heatmap->GetBinContent(x, y);
map->data()->coordToCell(x, y, &xc, &yc);
map->data()->setCell(xc, yc, data);
}
}
plot->axisRect()->setupFullAxesBox();
plot->xAxis->setLabel(xlabel);
plot->yAxis->setLabel(ylabel);
plot->rescaleAxes();
plot->legend->setVisible(false);
plot->replot();
return 0;
}