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Reference Guide
FITS_tutorial7.C
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1 /// \file
2 /// \ingroup tutorial_FITS
3 /// \notebook
4 ///
5 /// Open a FITS file that contains a catalog of astronomical objects
6 /// and dump some of its columns
7 ///
8 /// \macro_code
9 /// \macro_output
10 ///
11 /// \author Elizabeth Buckley-Geer
12 
13 void FITS_tutorial7()
14 {
15  // We are going to open a table from a FITS file
16  // and print out three columns for some of the objects.
17  // This table contains a logical data type so this tutorial tests
18  // that we can read it correctly
19 
20  TString dir = gROOT->GetTutorialDir();
21 
22  // Open the table
23  TFITSHDU hdu(dir + "/fitsio/sample5.fits[1]");
24 
25  // Read the ra, dec, flux_g and brick_primary columns
26 
27  std::unique_ptr<TVectorD> vec1(hdu.GetTabRealVectorColumn("ra"));
28  std::unique_ptr<TVectorD> vec2(hdu.GetTabRealVectorColumn("dec"));
29  std::unique_ptr<TVectorD> vec3(hdu.GetTabRealVectorColumn("flux_g"));
30  std::unique_ptr<TVectorD> vec4(hdu.GetTabRealVectorColumn("brick_primary"));
31 
32  for (auto i : ROOT::TSeqI(vec1->GetLwb(), vec1->GetUpb())) {
33  const auto bp = (*vec4)[i];
34  if (bp) {
35  const auto gflux = (*vec3)[i];
36  const auto ra = (*vec1)[i];
37  const auto dec = (*vec2)[i];
38  printf("RA %f DEC %f G-FLUX %f\n", ra, dec, gflux);
39  }
40  }
41 }
#define gROOT
Definition: TROOT.h:415
Basic string class.
Definition: TString.h:131
FITS file interface class.
Definition: TFITS.h:34
A pseudo container class which is a generator of indices.
Definition: TSeq.hxx:66