How to write prime in TLatex

[Songshaptak_De]

Hi, I want to write S’_{L} in the legend of my histogram, how can I put the prime symbol using TLatex in ROOT ?

ROOT Version: 5.34/09
Platform: Scientific Linux

[couet]

root [0] auto t = new TLatex(.5,.5,"this is prime: '")
root [1] t->Draw()

[Songshaptak_De]

But, this is the same as apostrophe.
I want like this S^\prime_L
Is there anyway to write this in TLatex ?

[couet]

auto t = new TLatex(.5,.5,"S^{'}_{L}")

[Wile_E_Coyote]

TMathText

[couet]

auto t = new TLatex(.5,.5,"S^{\\prime}_{L}")

or:

auto t = new TLatex(.5,.5,"S_{L}\\prime")

indeed simply use what you would use in LaTex.

[Songshaptak_De]

Can “S^{\prime}_{L}” be written inside legend->AddEntry() ?

[couet]

Yes sure. Note you need 2 “\”:

S^{\\prime}_{L}

[couet]

{
  TCanvas *c2 = new TCanvas("c2","c2",500,300);

  TLegend* leg = new TLegend(0.2, 0.2, .8, .8);

  TH1* h = new TH1F("", "", 1, 0, 1);

  leg->AddEntry(h, "Histogram \"h\"", "l");
  leg->AddEntry((TObject*)0, "", "");
  leg->AddEntry((TObject*)0, "Some text", "");
  leg->AddEntry((TObject*)0, "", "");
  leg->AddEntry(h, "Histogram \"h\" again", "l");
  leg->AddEntry(h, "TMathText: S^{\\prime}_{L}", "l");

  leg->Draw();
}

Note the TMathText limitation: TMathText rendering is not implemented for the PDF output. PostScript output should be used instead.

[Songshaptak_De]

Thanks for the showing the command to write prime in the the legend of the histogram.
But, there is one problem I am facing with this command is that - the statement that is written prior to S^{\\prime}_{L} gets printed in italics format and without any spaces like the one in the following picture. Is there a way to mitigate this problem ?

[couet]

TMathText renders text as Latex Math formulae. So it follows the Latex Math formulae rules (see a Latex manual). So yes, it is always italic, and yes the spaces are ignored. To make spaces you can for instance do:

  leg->AddEntry(h, "After\\;Mass\\;Cut, S^{\\prime}_{L}", "l");

[ferhue]

As a suggestion/alternative idea:

When I want full latex control, what I usually follow is Saving Canvas as TeX - ROOT

For the ‘italics’ issue, what I would do in that case is something like

"\\mathrm{After\\,Mass\\,Cut},\\;S^{\\prime}_{L}"

[Wile_E_Coyote]

Instead of “S_{L}^{\\prime}”, you may like “S_{L}{\\!\\!\\prime}” or “S_{L}{\\!\\!\\'}”.