FITS /BITS
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FITS /BITS

            [VECTOR\]FITS OutputFile.fits FROM InputFile.gdf /BITS Nbit

        The  number  of bits offers two controls: the data size and the encoding
        scheme. This value will be found in the resulting header under the  card
        BITPIX.

        Encoding scheme:
            It is controled by the Nbit sign.
            Positive sign means indexed encoding: the values are scaled as inte-
            gers distributed among the  2**abs(Nbit)  values.  The  forward  and
            back-conversion  from  actual  values to indexed values are based on
            the data extrema. Beware they must be up-to-date in the  GDF  header
            before  converting  a BITPIX>0 FITS (see command V\HEADER /EXTREMA)!
            Blank values are identified as  the  last  integer  of  the  indexed
            scale.
            Negative sign means the actual values are saved "as is" (IEEE float-
            ing point format). Blank values are saved as IEEE NaN.
        Data size:
            It is controled by the Nbit absolute value: 16, 32, or 64 will  con-
            sume  respectively  2, 4 and 8 bytes per value, with a direct impact
            of the file size.

        Nbits=+16 is worth only if the data dynamic (range of  values)  is  low,
        otherwise  value precision loss will happen (2**16 values are not enough
        to cover properly a large range of values). In the other  cases,  Nbit<0
        is  more  modern and should be prefered. The command supports Nbits +16,
        +32, -32, -64.