**in=***sds_file*- Input file (SDS HDF file)
**out=***fits_file*- Optional output FITS file. If no filename given, the input dataset is merely scanned and it’s rank and size are reported.
- select=
*file_number* - Select a
*file_number*(1 being the first) for output. Currently only one*fits*file at a time can be extracted. [Default:**1**]. - axis=
*axis_number* - If non-zero, this coordinate axis will be dumped as a 1D array in the fits file. Note the first axis is the one that described the fasted running index in the data-array (i.e. fortran array notation). A 0 is used if the 2/3D array is written. Default: 0.
- reorder=t|f
- Reorder the axes. Normally the data is transferred to the FITS
file "as is", without reordering, though SDS lists the axis backwards (NZ,NY,NX:
where NX is the fastest running axis in fortran sense, and in FITS normally
plotted horizontally). With
**reorder=t**all data is reordered, which can take large resources for large SDS files. - dummy=t|f
- Write dummy axis that have
dimension 1 also? [Default:
**t**] - wcs=t|f
- Add a WCS to the fits file, as much
as that is possible. By default (there is no keyword to change this yet)
the first pixel (1,1,1) will be the reference pixel, and CDELT will be
computed by the difference to the 2nd pixel along the appropriate axis.
If there is no 2nd pixel, CDELT will be 1. If there is a 3rd pixel and the
CDELT is different, a warning is posted. [Default:
**t**]

1) input SDS must be a 2D or 3D - output will be the corresponding FITS image map/cube

2) the whole SDS is read into memory, no slicing. Although this is fast, it limits the size of the cube to the (virtual) memory you have.

3) Only the required FITS header keywords NAXIS, NAXIS1, NAXIS2 and NAXIS3 are written out.

http://hdf.ncsa.uiuc.edu/fits/index.html (fitsbrowser::fits2sds,phdu2shs)

% tsd hdf100bg Found 3 scientific data sets in hdf100bg 1: R-VELOCITY AT TIME=2.00E+00(19,32) km/sec -> [608 elements of type: 5 (FLOAT32)] 2: PHI-VELOCITY AT TIME=2.00E+00(19,32) km/sec -> [608 elements of type: 5 (FLOAT32)] 3: DENSITY AT TIME=2.00E+00(19,32) Msolar/pc**2 -> [608 elements of type: 5 (FLOAT32)] % sdsfits hdf100bg map1.fits 3 reorder=f Data: DENSITY AT TIME=2.00E+00 Msolar/pc**2 1pe8.2 Polar map1.fits: writing as FITS file Data min/max = 0.00177725 362.925 % sdsfits hdf100bg map2.fits 3 reorder=t Data: DENSITY AT TIME=2.00E+00 Msolar/pc**2 1pe8.2 Polar map2.fits: writing as FITS file reorder: 19 x 32 Data min/max = 0.00177725 362.925

19-Jan-95V1.0 CreatedPJT 13-apr-95V1.1 added select=, fixed bug in 2D conversionPJT 13-apr-96V1.2 added axis=PJT 14-jan-03V1.4 added reorder=PJT 2-dec-04V1.5 added dummy=, and fixed some 3D data bugsPJT 11-dec-04V1.6 added wcs=, fixed some more bugs with 3D dataPJT