Version 5.2

The best method to read INES files in IDL is with the "MRDFITS'' function, which stores the data into an IDL structure with four tags: Wavelength, Flux, Sigma and Quality:

IDL> data=mrdfits('SWP25774LL.FITS',1,str='INES')
MRDFITS: Binary table. 4 columns by 495 rows.

IDL> help,data,/st
** Structure INES, 4 tags, length=16:

   WAVELENGTH      FLOAT           1150.58
   FLUX            FLOAT      -2.65123e-14
   SIGMA           FLOAT       3.98036e-14
   QUALITY         INT              0

IDL> help,data.flux

<Expression>    FLOAT     = Array(495)

IDL> for i=300,304 do print,data(i).wavelength,data(i).flux,data(i).sigma,data(i).quality

      1653.50  1.62347e-14  3.68273e-15       0
      1655.18  1.53256e-14  3.69914e-15     -32
      1656.85  1.96984e-14  3.80942e-15   -4128
      1658.53  1.57936e-14  3.67132e-15   -4128
      1660.21  1.22920e-14  3.64177e-15   -4096

MRDFITS also allows to select a range of rows and/or columns. To read a range of wavelengths:

IDL> data=mrdfits('LWP07371LL.FITS',1,str='INES',range=[200,300])

MRDFITS: Binary table.  4 columns by  101 rows.

IDL> help,data,/st

** Structure INES, 4 tags, length=16, refs=1:

   WAVELENGTH      FLOAT           2385.29
   FLUX            FLOAT       2.37237e-13
   SIGMA           FLOAT       3.38377e-14
   QUALITY         INT                   0

IDL> help,a.wavelength

<Expression>    FLOAT     = Array(101)

IDL> print,minmax(a.wavelength)

      2385.29      2652.22

To select columns:

IDL> data=mrdfits('LWP07371LL.FITS',1,columns=[1,2])

MRDFITS: Binary table.  4 columns by  562 rows.

IDL> help,data,/st

** Structure INES, 2 tags, length=8, refs=1:

   WAVELENGTH      FLOAT           1851.43
   FLUX            FLOAT       2.82831e-13

The bi-dimensional SILO files can be read with the command "READFITS":

IDL> silo=readfits('SWP43250.SILO')

% READFITS: File may contain FITS extensions
% READFITS: Now reading 640 by 80 array

IDL> help,silo

SILO            FLOAT     = Array(640, 80)

The bi-dimensional quality-flag image is stored as an image extension of the SILO file. It can also be read with "READFITS":

IDL> silo_nu=readfits('SWP43250.SILO',ext=1)

% READFITS: Reading FITS extension of type IMAGE
% READFITS: Now reading 640 by 80 array

IDL> help,silo_nu

SILO_NU         INT       = Array(640, 80)

IDL> print,minmax(silo_nu)

-16384       0