Ratio plot for multiple graphs

[Shreya1]

Is it possible to create a Ratio Plot for two graphs from two different root files? ___
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[Wile_E_Coyote]

Plotting the difference between a graph and the fitting function

Hello, I’m a ROOT newbie (and computing newbie in general). I don’t know the proper terminology to explain what I want to do, but it’s the following: Let’s say I have a plot of a fitted graph with error bars. I want to make a plot under the main graph of the difference between the points of the graph and their respective points of the function. This other plot must also have the same error bars as the main graph. I already know how to plot the main fitted graph. The following image is an examp…

[Shreya1]

Hi Wile_E_Coyote,
Many thanks for the reply. I tried to make use of this concept. The problem I face is I cannot use Divide function for TGraph. And if I go with more traditional way, I use SetPoint(i,x,y) function. The problem I face in SetPoint is that it takes in “double” type parameters for the points while GetX() or GetY() function for TGraph returns double*.
Any idea how to fix this?

[Wile_E_Coyote]

Try graph->GetX()[i] and graph->GetY()[i].

[Shreya1]

Thanks a lot!! It works. I understood where I was wrong.