Stats box title

ROOT
1

Hello,

I have been trying to write an individualized title for each of my stats boxes. I have tried to use TLists, as shown in the TPaveStats “statistics box editing” example ( root.cern.ch/root/html/TPaveStats.html#PS03 ). Unlike that example, I’m using a TGraph and having some serious issues. I suppose I could go in and add a TPaveText above each stats box, but in my real work I’m plotting over half a dozen fits - having a title seems like a reasonable approach. Any help would be most appreciated.

Below I will post some sample code with dummy variables to illustrate my method.

With much thanks,
Josh Magee

The following “short, self contained, correct” example macro compiles in root:
root[0] .L test_function.C++g"
root[1] test_function()

This produces the dummy plot but the stats box doesn’t include the “title”.

//ROOT based libraries
#include <TROOT.h>
#include <TCanvas.h>
#include <TStyle.h>
#include <TGraph.h>
#include <TList.h>
#include <TF1.h>
#include <TPaveStats.h>

void test_function(void) {
  gROOT->Reset();
  gROOT->SetStyle("Modern");
  gStyle->SetOptFit(1111);

  const int n = 3;
  const float x_values[n] = {1,2,3}; //independent variable
  const float y_values[n] = {3,4,5}; //dependent variable

  TGraph *graph = new TGraph(n,x_values,y_values);

  TCanvas *canvas = new TCanvas("canvas","title");
  graph->Draw("ap");

  canvas->Modified();
  canvas->Update();

  TF1 *fFit = new TF1("fFit","pol1");
  graph->Fit("fFit","sames");

  canvas->Modified();
  canvas->Update();

  TList *list;
  TPaveStats *stats = (TPaveStats*) graph->GetListOfFunctions()->FindObject("stats");
  if (stats) { //check to make sure *stats isn't null
    stats->SetTextColor(kBlue);
    TList *list = stats->GetListOfLines();
    TText *title_line = new TText(0,0,"Stats Box Title");
    list->AddFirst(title_line); //add new line to top of stats box ??
    stats->Draw("sames");
  }

  canvas->Modified();
  canvas->Update();

} //conclude example macro
2

h->SetStats(0);
is the key line in the macro you took as example (to avoid stats recomputing).
there is no equivalent for graphs

3

Couet,

Thank you. Just to be clear: there is no way to alter a TGraph’s StatsBox, by adding and removing lines? (aside from the SetOptStat() methods which configure the statistics shown). But I can do that for a THF?

Thank you again,
Josh

4

The graph stat box is ion fact the histogram one.
It is redrawn each time the graph is drawn.
You better produce your TPaveStats yourself is you need a specific one.