Logo ROOT   6.10/09
Reference Guide
FITS_tutorial4.C File Reference

Detailed Description

Open a FITS file whose primary array represents a spectrum (flux vs wavelength)

void FITS_tutorial4()
{
printf("\n\n--------------------------------\n");
printf("WELCOME TO FITS tutorial #4 !!!!\n");
printf("--------------------------------\n");
printf("We're gonna open a FITS file that contains the\n");
printf("primary HDU and a little data table.\n");
printf("The data table is extension #1 and it has 2 rows.\n");
printf("We want to read only the rows that have the column\n");
printf("named DATAMAX greater than 2e-15 (there's only 1\n");
printf("matching row)\n");
printf("Data copyright: NASA\n\n");
if (!gROOT->IsBatch()) {
//printf("Press ENTER to start..."); getchar();
}
TString dir = gSystem->DirName(__FILE__);
//Open the table extension number 1)
TFITSHDU *hdu = new TFITSHDU(dir+"/sample2.fits[1][DATAMAX > 2e-15]");
if (hdu == 0) {
printf("ERROR: could not access the HDU\n"); return;
}
//printf("Press ENTER to see information about the table's columns..."); getchar();
hdu->Print("T");
printf("\n\n........................................\n");
printf("Press ENTER to see full table contents (maybe you should resize\n");
//printf("this window as large as possible before)..."); getchar();
hdu->Print("T+");
printf("\n\n........................................\n");
//printf("Press ENTER to get only the DATAMAX value of the matched row..."); getchar();
TVectorD *v = hdu->GetTabRealVectorColumn("DATAMAX");
printf("%lg\n", (*v)[0]);
printf("Does the matched row have DATAMAX > 2e-15? :-)\n");
//Clean up
delete v;
delete hdu;
}
Author
Claudi Martinez

Definition in file FITS_tutorial4.C.