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sdinfo - sdfits (BINTABLE) info and benchmark


sdinfo [parameter=value]


sdinfo list some tabular properties of an SDFITS (and some dialects) file, and has options to benchmark some basic operations.

SDFITS files have a BINTABLE extension named "SINGLE DISH", and is used to store single dish spectra and all associated variables. This program was only written to provide size info and can run a few basic benchmarks. A few known dialects to this are known: "CIMAFITS" (Arecibo) and "MATRIX" (30m/CLASS), the latter designates the spectrum via a "SPECTRUM" column name, instead of the more common "DATA" column name.


The following parameters are recognized in any order if the keyword is also given:
Input SDFITS fits file. Multiple files can be given as well, as a space or comma separated this. No default.
If true, some basic statistics will be computed. You also need this option if a row (see row= below) is output.
Maximum moment some statistics will be computed. mom=0 will just sum, and be much faster than general moment computation. [2].
Column names to track. Currently it just gives the column number and format used. Default: not used.
A list of dimensions how the data-block should be processed. The procedure of processing is set by the proc= keyword. For example dims=2,11,2,2,4. The product of the dimensions should be NAXIS2 (or less than) from the BINTABLE. Default: not used.
The procedure of processing can be set with this. Currently only one specific example (see EXAMPLES below) for ngc5291 is implemented. Options would be PS (Position Switching), FS (frequency switching), NOD (nodding), TP (total power). NOT IMPLEMENTED YET, if ever.
Override the number of channels found in the data. Some dataset will find nchan=0 and it will be useful to set this here. This number is related to NAXIS1 in the BINTABLE.
If used, this row (0 being the first) will be output as an ascii spectrum. This spectrum has two columns: channel number (0 being the first) and the spectrum value, native units.
How many times the procedure should be processed. This will only re-execute the procedure, not the alloc/free that are needed for this. Using 0 will bypass the procedure. Default: 1


The following example takes all fits files matching a particular pattern and summarize their contents.
    ls *.?.fits > dirin.lis
    sdinfo in=@dirin.lis : Nrows: 2168   Ncols: 70  Nchan: 32768 : Nrows: 2168   Ncols: 70  Nchan: 32768 : Nrows: 2168   Ncols: 70  Nchan: 32768 : Nrows: 3004   Ncols: 70  Nchan: 32768 : Nrows: 3004   Ncols: 70  Nchan: 32768 : Nrows: 3004   Ncols: 70  Nchan: 32768
Here is a benchmark of the ngc5291 example:
    time sdinfo ngc5291.fits dims=2,11,2,2,4 bench=100 help=c
    ### nemo Debug Info: ngc5291.fits : Nrows: 352   Ncols: 46  Nchan: 32768
    ### Warning [sdinfo]: PS Reduction procedure in 5 dimensions; data_col
= 7
    ### nemo Debug Info: DATA6 3.71521 0.0366262 3.30351     1.42437
    ### nemo Debug Info: CPU_USAGE sdinfo : 3.09    3.04 0.04  0.00 0.00  1803498650
    real    0m3.095s
    user    0m3.047s
    sys     0m0.048s

Here is a way to plot a spectrum:

    sdinfo ngc5291.fits t row=11 | tabplot - 

See Also

scanfits(1NEMO) , fitshead(1NEMO)




Peter Teuben

Update History

23-Nov-2019    V0.1 Created    PJT
14-dec-2019    V0.4 dimension analysis w/ n5291    PJT
18-dec-2019    V0.7 Handle CIMAFITS and MATRIX extensions    PJT

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