psview.C File Reference

Detailed Description

An example how to display PS, EPS, PDF files in canvas.

To load a PS file in a TCanvas, the ghostscript program needs to be install.

• On most unix systems it is installed by default.
• On Windows it has to be installed from http://pages.cs.wisc.edu/~ghost/ also the place where gswin32c.exe sits should be added in the PATH. One way to do it is:
  1. Start the Control Panel
  2. Double click on System 3, Open the "Advanced" tab
  3. Click on the "Environment Variables" button
  4. Find "Path" in "System variable list", click on it.
  5. Click on the "Edit" button.
  6. In the "Variable value" field add the path of gswin32c (after a ";") it should be something like: "C:\Program Files\gs\gs8.13\bin"
  7. click "OK" as much as needed.

#include "TROOT.h"
#include "TCanvas.h"
#include "TImage.h"

void psview()
{
   // set to batch mode -> do not display graphics
   gROOT->SetBatch(1);

   // create a PostScript file
   TString dir = gROOT->GetTutorialDir();
   dir.Append("/graphics/feynman.C");
   gROOT->Macro(dir);
   gPad->Print("feynman.eps");

   // back to graphics mode
   gROOT->SetBatch(0);

   // create an image from PS file
   TImage *ps = TImage::Open("feynman.eps");

   if (!ps) {
      printf("GhostScript (gs) program must be installed\n");
      return;
   }

   new TCanvas("psexam", "Example how to display PS file in canvas", 600, 400);
   TLatex *tex = new TLatex(0.06,0.9,"The picture below has been loaded from a PS file:");
   tex->Draw();

   TPad *eps = new TPad("eps", "eps", 0., 0., 1., 0.75);
   eps->Draw();
   eps->cd();
   ps->Draw("xxx");
}

Author

Valeriy Onoutchin

Definition in file psview.C.