doc/v628/FITS__tutorial1_8C.html

void FITS_tutorial1()

{

   // Here we open a FITS file that contains only the primary HDU, consisting on an image.

   // The object you will see is a snapshot of the NGC7662 nebula,

   // which was taken by the author on November 2009 in Barcelona.


   TString dir = gROOT->GetTutorialDir();


   // Open primary HDU from file

   TFITSHDU hdu(dir + "/fitsio/sample1.fits");


   // Dump the HDUs within the FITS file

   // and also their metadata

   // printf("Press ENTER to see summary of all data stored in the file:"); getchar();


   hdu.Print("F+");


   // Here we get the exposure time.

   printf("Exposure time = %s\n", hdu.GetKeywordValue("EXPTIME").Data());


   // Read the primary array as a matrix, selecting only layer 0.

   // This function may be useful to do image processing, e.g. custom filtering


   std::unique_ptr<TMatrixD> mat(hdu.ReadAsMatrix(0));

   mat->Print();


   // Read the primary array as an image, selecting only layer 0.

   TImage * im = (TImage *)hdu.ReadAsImage(0);


   // Read the primary array as a histogram. Depending on array dimensions, the returned

   // histogram will be 1D, 2D or 3D.

   TH1 * hist = (TH1 *)hdu.ReadAsHistogram();


   auto c = new TCanvas("c1", "FITS tutorial #1", 1400, 800);

   c->Divide(2, 1);

   c->cd(1);

   im->Draw();

   c->cd(2);

   hist->Draw("COL");

}

c
#define c(i)
Definition RSha256.hxx:101

gROOT
#define gROOT
Definition TROOT.h:405

TCanvas
The Canvas class.
Definition TCanvas.h:23

TFITSHDU
FITS file interface class.
Definition TFITS.h:35

TH1
TH1 is the base class of all histogram classes in ROOT.
Definition TH1.h:58

TH1::Draw
void Draw(Option_t *option="") override
Draw this histogram with options.
Definition TH1.cxx:3060

TImage
An abstract interface to image processing library.
Definition TImage.h:29

TObject::Draw
virtual void Draw(Option_t *option="")
Default Draw method for all objects.
Definition TObject.cxx:274

TString
Basic string class.
Definition TString.h:139