At root.cern.ch/root/html/THistPainter.html it is stated that
"CONT0" Draw a contour plot using surface colors to distinguish contours.
“CONT1” Draw a contour plot using line styles to distinguish contours.
I have tested both (as well as CONT2,3,4,5). Actually I found them very similar (not identical) in the graphic outcome, although the behaviour is quite different. First my piece of code, below the question:
int xChannels=4096;
int yChannels=1024;
Int_t n_col=10;
TH2D *hpha = new TH2D("Sep",pha_char,
xChannels,0,xChannels-1,yChannels,0,yChannels-1);
for (Int_t jx = 0; jx < xChannels; jx++)
{
for(Int_t jy = 0; jy < yChannels; jy++)
{
hpha->SetBinContent(jx,jy, SepMatrix[jy*xChannels + jx]);
}
}
gStyle->SetPalette(1);
gStyle->SetOptStat(0);
hpha->SetMarkerStyle(2);
hpha->SetMarkerSize(5);
hpha->SetContour(n_col, contours);
// hpha->Draw("CONT0 LOGZ"); // test case: 42 s for Canvas update, 870 kB eps
hpha->Draw("CONT1 LOGZ"); // test case: 2s for Canvas update, 5.2 MB eps
Please note the matrix size, 4096x1024.
If I use CONT0 on a test case, I get a very slow updating of the canvas (~ 42 s), but storing an EPS file from the canvas is efficient (small size, quick process). If I use CONT1, the screen output is ready in (~ 2 s), but the EPS storage becomes lengthy and large in size. Is that a common experience? Should I improve my code in some way to combine both beneficial effects? My idea is to insert a checkbutton “EPS output” in the main GUI frame.