FITS_tutorial2.C File Reference

Detailed Description

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

 
void FITS_tutorial2()
{
   // We're gonna open a FITS file that contains the primary HDU and a little data table.
   // The primary HDU is an array of 2 rows by 2040 columns, and they represent a radiation
   // spectrum. The first row contains the flux data, whereas the second row the wavelengths.
   // Data copyright: NASA
 
   TString dir = gROOT->GetTutorialDir();
 
   // Open primary HDU from file
   TFITSHDU hdu(dir + "/fitsio/sample2.fits");
 
   // Dump the HDUs within the FITS file
   // and also their metadata
   hdu.Print("F+");
 
   // We now generate a TGraph from vectors
   std::unique_ptr<TVectorD> Y(hdu.GetArrayRow(0));
   std::unique_ptr<TVectorD> X(hdu.GetArrayRow(1));
   TGraph gr(*X,*Y);
 
   // Show the graphic
   auto c = new TCanvas("c1", "FITS tutorial #2", 800, 800);
   gr.SetFillColor(kRed);
   gr.DrawClone("BA");
}

 
Total: 2 HDUs
   [0] IMAGE (PRIMARY)
      SIMPLE     = T / Standard FITS format
      BITPIX     = -32 / 32 bit IEEE floating point numbers
      NAXIS      = 2 / Number of axes
      NAXIS1     = 2064 / 
      NAXIS2     = 2 / 
      EXTEND     = T / There may be standard extensions
      OPSIZE     = 832 / PSIZE of original image
      ORIGIN     = 'ST-DADS ' / Institution that originated the FITS file
      FITSDATE   = '12/07/94' / Date FITS file was created
      FILENAME   = 'y19g0309t_cvt.c2h' / Original GEIS header file name with _cvt
      ODATTYPE   = 'FLOATING' / Original datatype
      SDASMGNU   = 2 / GCOUNT of original image
      DADSFILE   = 'Y19G0309T.C2F' / 
      DADSCLAS   = 'CAL     ' / 
      DADSDATE   = '12-JUL-1994 02:44:39' / 
      CRVAL1     = 1.0000000000000 / 
      CRPIX1     = 1.0000000000000 / 
      CD1_1      = 1.0000000000000 / 
      DATAMIN    = 0.00000000000000 / 
      DATAMAX    = 2.7387550387959E-15 / 
      RA_APER    = 182.63573015260 / 
      DEC_APER   = 39.405888372580 / 
      FILLCNT    = 0 / 
      ERRCNT     = 0 / 
      FPKTTIME   = 49099.133531036 / 
      LPKTTIME   = 49099.133541164 / 
      CTYPE1     = 'PIXEL   ' / 
      APER_POS   = 'SINGLE  ' / 
      PASS_DIR   = 0 / 
      YPOS       = -1516.0000000000 / 
      YTYPE      = 'OBJ     ' / 
      EXPOSURE   = 31.249689102173 / 
      X_OFFSET   = 0.00000000000000 / 
      Y_OFFSET   = 0.00000000000000 / 
                 =  / 
                 =  /          / GROUP PARAMETERS: OSS
                 =  / 
                 =  /          / GROUP PARAMETERS: PODPS
                 =  / 
                 =  /          / FOS DATA DESCRIPTOR KEYWORDS
      INSTRUME   = 'FOS               ' / instrument in use
      ROOTNAME   = 'Y19G0309T         ' / rootname of the observation set
      FILETYPE   = 'ERR     ' / file type
      BUNIT      = 'ERGS/CM**2/S/A' / brightness units
                 =  / 
                 =  /          / GENERIC CONVERSION KEYWORDS
      HEADER     = T / science header line exists
      TRAILER    = F / reject array exists
      YWRDSLIN   = 516 / science words per packet
      YLINSFRM   = 5 / packets per frame
                 =  / 
                 =  /          / CALIBRATION FLAGS AND INDICATORS
      GRNDMODE   = 'SPECTROSCOPY      ' / ground software mode
      DETECTOR   = 'AMBER             ' / detector in use: amber, blue
      APER_ID    = 'B-2               ' / aperture id
      POLAR_ID   = 'C                 ' / polarizer id
      POLANG     = 0.0000000E+00 / initial angular position of polarizer
      FGWA_ID    = 'H57               ' / FGWA id
      FCHNL      = 0 / first channel
      NCHNLS     = 512 / number of channels
      OVERSCAN   = 5 / overscan number
      NXSTEPS    = 4 / number of x steps
      YFGIMPEN   = T / onboard GIMP correction enabled (T/F)
      YFGIMPER   = 'NO                ' / error in onboard GIMP correction (YES/NO)
                 =  / 
                 =  /          / CALIBRATION REFERENCE FILES AND TABLES
      DEFDDTBL   = F / UDL disabled diode table used
      BACHFILE   = 'yref$b3m1128fy.r0h' / background header file
      FL1HFILE   = 'yref$baf13103y.r1h' / first flat-field header file
      FL2HFILE   = 'yref$n/a          ' / second flat-field header file
      IV1HFILE   = 'yref$c3u13412y.r2h' / first inverse sensitivity header file
      IV2HFILE   = 'yref$n/a          ' / second inverse sensitivity header file
      RETHFILE   = 'yref$n/a          ' / waveplate retardation header file
      DDTHFILE   = 'yref$c861559ay.r4h' / disabled diode table header file
      DQ1HFILE   = 'yref$b2f1301qy.r5h' / first data quality initialization header file
      DQ2HFILE   = 'yref$n/a          ' / second data quality initialization header file
      CCG2       = 'mtab$a3d1145ly.cmg' / paired pulse correction parameters
      CCS0       = 'ytab$a3d1145dy.cy0' / aperture parameters
      CCS1       = 'ytab$aaj0732ay.cy1' / aperture position parameters
      CCS2       = 'ytab$a3d1145fy.cy2' / sky emission line regions
      CCS3       = 'ytab$a3d1145gy.cy3' / big and sky filter widths and prism X0
      CCS4       = 'ytab$b9d1019my.cy4' / polarimetry parameters
      CCS5       = 'ytab$a3d1145jy.cy5' / sky shifts
      CCS6       = 'ytab$bck10546y.cy6' / wavelength coefficients
      CCS7       = 'ytab$ba910502y.cy7' / GIMP correction scale factores
      CCS8       = 'ytab$ba31407ly.cy8' / predicted background count rates
                 =  / 
                 =  /          / CALIBRATION SWITCHES
      CNT_CORR   = 'COMPLETE' / count to count rate conversion
      OFF_CORR   = 'OMIT              ' / GIMP correction
      PPC_CORR   = 'COMPLETE' / paired pulse correction
      BAC_CORR   = 'COMPLETE' / background subtraction
      GMF_CORR   = 'COMPLETE' / scale reference background
      FLT_CORR   = 'COMPLETE' / flat-fielding
      SKY_CORR   = 'COMPLETE' / sky subtraction
      WAV_CORR   = 'COMPLETE' / wavelength scale generation
      FLX_CORR   = 'COMPLETE' / flux scale generation
      ERR_CORR   = 'COMPLETE' / propagated error computation
      MOD_CORR   = 'OMIT              ' / ground software mode dependent reductions
                 =  / 
                 =  /          / PATTERN KEYWORDS
      INTS       = 2 / number of integrations
      YBASE      = -1516 / y base
      YRANGE     = 0 / y range
      YSTEPS     = 1 / number of y steps
      YSPACE     = 0.0000000E+00 / yrange * 32 / ysteps
      SLICES     = 1 / number of time slices
      NPAT       = 12 / number of patterns per readout
      NREAD      = 2 / number of readouts per memory clear
      NMCLEARS   = 1 / number of memory clears per acquisition
      YSTEP1     = 'OBJ               ' / first ystep data type: OBJ, SKY, BCK, NUL
      YSTEP2     = 'NUL               ' / second ystep data type: OBJ, SKY, BCK, NUL
      YSTEP3     = 'NUL               ' / third ystep data type: OBJ, SKY, BCK, NUL
      XBASE      = 0 / X-deflection base
      XPITCH     = 1521 / X-deflection pitch between diode
      YPITCH     = 1834 / Y-deflection pitch
                 =  / 
                 =  /          / CALIBRATION KEYWORDS
      LIVETIME   = 33333 / accumulator open time  (unit=7.8125 microsec)
      DEADTIME   = 1280 / accumulator close time (unit=7.8125 microsec)
      MAXCLK     = 0 / maximum clock count
      PA_APER    = 0.2462417E+03 / position ang of aperture used with target (deg)
      NOISELM    = 65535 / burst noise rejection limit
      OFFS_TAB   = 'n/a               ' / GIMP offsets (post-pipeline processing only)
      MINWAVE    = 4569.102 / minimum wavelength (angstroms)
      MAXWAVE    = 6817.517 / maximum wavelength (angstroms)
                 =  / 
                 =  /          / STATISTICAL KEYWORDS
      DATE       = '22/04/93          ' / date this file was written (dd/mm/yy)
      PKTFMT     = 96 / packet format code
      PODPSFF    = '0                 ' / 0=(no podps fill), 1=(podps fill present)
      STDCFFF    = '0                 ' / 0=(no st dcf fill), 1=(st dcf fill present)
      STDCFFP    = '0000              ' / st dcf fill pattern (hex)
                 =  / 
                 =  /          / APERTURE POSITION
      RA_APER1   = 0.1826357301526E+03 / right ascension of the aperture (deg)
      DECAPER1   = 0.3940588837258E+02 / declination of the aperture (deg)
                 =  / 
                 =  /          / EXPOSURE INFORMATION
      EQUINOX    = 'J2000             ' / equinox of the celestial coordinate system
      SUNANGLE   = 0.1225114E+03 / angle between sun and V1 axis (deg)
      MOONANGL   = 0.1191039E+03 / angle between moon and V1 axis (deg)
      SUN_ALT    = 0.4515910E+02 / altitude of the sun above Earth's limb (deg)
      FGSLOCK    = 'COARSE            ' / commanded FGS lock (FINE,COARSE,GYROS,UNKNOWN)
                 =  / 
      DATE-OBS   = '22/04/93          ' / UT date of start of observation (dd/mm/yy)
      TIME-OBS   = '03:12:17          ' / UT time of start of observation (hh:mm:ss)
      EXPSTART   = 0.4909913202874E+05 / exposure start time (Modified Julian Date)
      EXPEND     = 0.4909913505303E+05 / exposure end time (Modified Julian Date)
      EXPTIME    = 0.2499975E+03 / exposure duration (seconds)--calculated
      EXPFLAG    = 'NORMAL            ' / Exposure interruption indicator
                 =  / 
                 =  /          / TARGET & PROPOSAL ID
      TARGNAME   = 'NGC4151-CLOUD2    ' / proposer's target name
      RA_TARG    = 0.1826357301526E+03 / right ascension of the target (deg) (J2000)
      DEC_TARG   = 0.3940588837258E+02 / declination of the target (deg) (J2000)
                 =  / 
      PROPOSID   = 4220 / PEP proposal identifier
      PEP_EXPO   = '174.0000000       ' / PEP exposure identifier including sequence
      LINENUM    = '174.000           ' / PEP proposal line number
      SEQLINE    = '                  ' / PEP line number of defined sequence
      SEQNAME    = '                  ' / PEP define/use sequence name
 
   [1] ASCII TABLE ('y19g0309t.c2h.tab')
      XTENSION   = 'TABLE   '
      BITPIX     = 8
      NAXIS      = 2
      NAXIS1     = 336
      NAXIS2     = 2
      PCOUNT     = 0
      GCOUNT     = 1
      TFIELDS    = 19
      EXTNAME    = 'y19g0309t.c2h.tab'
      TTYPE1     = 'CRVAL1  '
      CRVAL1     = 'pixel number'
      TFORM1     = 'D25.16  '
      TBCOL1     = 1
      TTYPE2     = 'CRPIX1  '
      CRPIX1     = 'pixel number of reference pixel'
      TFORM2     = 'E15.7   '
      TBCOL2     = 29
      TTYPE3     = 'CD1_1   '
      CD1_1      = 'pixel increment'
      TFORM3     = 'E15.7   '
      TBCOL3     = 45
      TTYPE4     = 'DATAMIN '
      DATAMIN    = 'the minimum value of the data'
      TFORM4     = 'E15.7   '
      TBCOL4     = 61
      TTYPE5     = 'DATAMAX '
      DATAMAX    = 'the maximum value of the data'
      TFORM5     = 'E15.7   '
      TBCOL5     = 77
      TTYPE6     = 'RA_APER '
      RA_APER    = 'right ascension of aperture (deg)'
      TFORM6     = 'D25.16  '
      TBCOL6     = 93
      TTYPE7     = 'DEC_APER'
      DEC_APER   = 'declination of aperture (deg)'
      TFORM7     = 'D25.16  '
      TBCOL7     = 121
      TTYPE8     = 'FILLCNT '
      FILLCNT    = 'number of segments containing fill'
      TFORM8     = 'I11     '
      TBCOL8     = 149
      TTYPE9     = 'ERRCNT  '
      ERRCNT     = 'the error count of the data'
      TFORM9     = 'I11     '
      TBCOL9     = 161
      TTYPE10    = 'FPKTTIME'
      FPKTTIME   = 'the time of the first packet'
      TFORM10    = 'D25.16  '
      TBCOL10    = 173
      TTYPE11    = 'LPKTTIME'
      LPKTTIME   = 'the time of the last packet'
      TFORM11    = 'D25.16  '
      TBCOL11    = 201
      TTYPE12    = 'CTYPE1  '
      CTYPE1     = 'the first coordinate type'
      TFORM12    = 'A8      '
      TBCOL12    = 229
      TTYPE13    = 'APER_POS'
      APER_POS   = 'aperture used'
      TFORM13    = 'A8      '
      TBCOL13    = 241
      TTYPE14    = 'PASS_DIR'
      PASS_DIR   = 'polarization pass direction'
      TFORM14    = 'I11     '
      TBCOL14    = 253
      TTYPE15    = 'YPOS    '
      YPOS       = 'y-position on photocathode'
      TFORM15    = 'E15.7   '
      TBCOL15    = 265
      TTYPE16    = 'YTYPE   '
      YTYPE      = 'observation type: OBJ, SKY, BCK'
      TFORM16    = 'A4      '
      TBCOL16    = 281
      TTYPE17    = 'EXPOSURE'
      EXPOSURE   = 'exposure time per pixel (seconds)'
      TFORM17    = 'E15.7   '
      TBCOL17    = 289
      TTYPE18    = 'X_OFFSET'
      X_OFFSET   = 'x_offset for GIMP correction (diodes)'
      TFORM18    = 'E15.7   '
      TBCOL18    = 305
      TTYPE19    = 'Y_OFFSET'
      Y_OFFSET   = 'y_offset for GIMP correction (defl.units)'
      TFORM19    = 'E15.7   '
      TBCOL19    = 321
 

Author

Claudi Martinez

Definition in file FITS_tutorial2.C.