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Reference Guide
FITS_tutorial4.C
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1 /// \file
2 /// \ingroup tutorial_FITS
3 /// \notebook
4 ///
5 /// Open a FITS file whose primary array represents
6 /// a spectrum (flux vs wavelength).
7 ///
8 /// \macro_code
9 /// \macro_output
10 ///
11 /// \author Claudi Martinez
12 
13 void FITS_tutorial4()
14 {
15  // We open a FITS file that contains the primary HDU and a little data table.
16  // The data table is extension #1 and it has 2 rows.
17  // We want to read only the rows that have the column named DATAMAX greater than 2e-15 (there's only 1
18  // matching row Data copyright: NASA
19 
20  TString dir = gROOT->GetTutorialDir();
21 
22  // Open the table extension number 1)
23  TFITSHDU hdu(dir + "/fitsio/sample2.fits[1][DATAMAX > 2e-15]");
24 
25  hdu.Print("T");
26 
27  hdu.Print("T+");
28 
29  std::unique_ptr<TVectorD> vp(hdu.GetTabRealVectorColumn("DATAMAX"));
30  const auto &v = *vp;
31  std::cout << "v[0] = " << v[0] << std::endl;
32  std::cout << "Does the matched row have DATAMAX > 2e-15? :-)" << std::endl;
33 }
#define gROOT
Definition: TROOT.h:415
Basic string class.
Definition: TString.h:131
FITS file interface class.
Definition: TFITS.h:34