TRatioPlot interference

[calbet]

Dear experts,
I draw several 4 hist, then on the bottom I want to plot the ratio of only 2 of them. When I used (1),
after I call TRatioPlot, it does not draw the 4 hist anymore but only the 2 hist that I call to make the TRatioPlot (2). Also, it does not event Draw them “Normalized” as I asked. Normaly I shoud have this (3) on the top pad. Is it normal that TRatioPlot ignore the previous requested? How can I solve this?
Regards

(1)
http://calpas.web.cern.ch/calpas/plot.cc

(2)

(3)

[couet]

I cannot execute your macro.
MuonRates_ttbar_road60.root does not exist

[calbet]

Dear Couet,
thank you. The 3 root files needed are here (1). You also need the file (2) for the style.
Regards

(1)
http://calpas.web.cern.ch/calpas/MuonRates_ttbar_road60.root
http://calpas.web.cern.ch/calpas/MuonRates_ttbar_road90.root
http://calpas.web.cern.ch/calpas/MuonRates_ttbar_road120.root

(2)
http://calpas.web.cern.ch/calpas/rootstyle.cc

[couet]

You should first draw the ratio plot and then draw (with option same) on top the other histograms you want to see.

[calbet]

Dear Couet,
I tried this in (1) but it’s not working. The hist looks like this (2), so sill only 2 hist, and no color etc…
To run this new code, you need 2 more root files (3).
Regards

(1)
http://calpas.web.cern.ch/calpas/plot.cc

(2)

(3)
http://calpas.web.cern.ch/calpas/MuonRates_ttbar_road500.root
http://calpas.web.cern.ch/calpas/MuonRates_ttbar_road1000.root

[couet]

[...]
               ratio->GetUpperPad()->cd();
               hist[file][type][pt][var]->Draw("hist same");
[...]

[calbet]

Dear Couet,

• ok thank you, I’ll try that.
• is there a way to do not draw the large error bars on the TRatioPlot plot when the division return “nan”? Indeed we have a lot of bars in the ratio plot while there are not values.
  Regards

[couet]

@calbet

is there a way to do not draw the large error bars on the TRatio plot when the division return “nan”? Indeed we have a lot of bars in the ratio plot while there are not values.

You should set the error properly and may be set the error ro 0 hone your computation leads to a wrong result.
It is up to you to decide what is the best solution in that case.

[calbet]

Dear Couet,

• on the top pad, do you understand why it draws the error bars only for the 1st hist while there is not “e” option in the Draw (1)?
• I modified a the code, you can see the new one here (2).
  Regards

(1)

(2)
http://calpas.web.cern.ch/calpas/plot.cc

[couet]

If you do not want the errors bars draw the histogram with the option hist

[calbet]

Yes, I’m already using “hist”, but it draw still the error bars.
Regards

[couet]

Indeed you are using the option hist for the histograms you are drawing in the top pad on top of the ratio plot (as I told your earlier). But the errors bars you see are coming from the histogram drawn via the ratio plot itself. If you look at the documentation, you will find out that it is possible to change the drawing option of both histograms used to make the ratio plot. In your case: ratio->SetH2DrawOpt("hist"); is the command to be added before ratio->Draw();

[calbet]

Dear Couet,

• Thank you it works fine.
• I still want to plot several ratio plots on the lower pad. I saw a suggestion here (1) but it did not work, so I just use something like (2) but it seems to plot the entire frame each time instead of just the curve only, see (3). The complete code is here (4). Do you see what is wrong?
  Regards

(1)

Compare several histograms with TRatioPlot

Hi @couet thanks for the feedback, it is useful! I guess I am also missing another piece of info: I also want to retrieve the histograms so that I can plot them on the (top and bottom) canvases. Let me give you an example: ratio1 = TRatioPlot(h1,h0) ratio2 = TRatioPlot(h2,h0) In the end I’d like to have h0, h1 and h2 displayed on the top canvas and h1/h0 and h2/h0 displayed on the bottom canvas. Thanks! Francesco

(2)
auto ratio_noniso = new TRatioPlot(hist_prompt, hist_fake_noniso);
auto ratio_hadron = new TRatioPlot(hist_prompt, hist_fake_hadron);
auto ratio_other = new TRatioPlot(hist_prompt, hist_fake_other);
//
ratio_noniso → SetH2DrawOpt(“hist”);
ratio_noniso → Draw();
//
ratio_noniso → GetLowerPad()->cd();
ratio_hadron → Draw(“same”);
ratio_other → Draw(“same”);

(3)

(4)
http://calpas.web.cern.ch/calpas/plot.cc

[couet]

… I am not completely sure I understand what you are trying to do … let me see…

[calbet]

I just want to plot several ratio plots on the lower pad.
Regards

[couet]

But if you want the ratio of two other histograms why do you need a new TRatioPLot ? you just need to divide the two histograms, do a cd() to the lower pad of the TRatioPlot and plot (with option same) the result of the division you just did ?

[calbet]

Dear Couet,

• thank you, it works fine.
• which option should I use to do not draw the error bars of Tratio? As you can see here (1), there are error bar for the black hist on the bottom pad, as I use it to make the TRatio?
• Is it possible to plot only the Tratio frame (pad, axis, etc…) and not the graph? Then I could add the hist that I made myself?
  Regards

(1)

[couet]

The ratio on the bottom pad is a TGraphAsymmErrors it makes no sense to plot it with errors bars.

[calbet]

Dear Couet,
sorry, do you mean that I shoud not use error bars?
Regards

[couet]

I mean that you use TRatioPlot, the bottom is produced automatically from the two histograms you gave. The bottom plot is generated via a TGraphAsymmErrors, which, obviously, has errors bars.