18.18 MAP_SMOOTH

[CLEAN\]MAP_SMOOTH WhichOne Nc [Result] [/ASYMMETRIC]

Smooth a 3-D data cubes by Nc channels along the velocity axis.

      Nc   number of channels to be averaged in smoothing.

WhichOne indicates which data cube must be compressed. Allowed values are

      - Built-in buffers DIRTY, CLEAN, SKY, SINGLE or *, which means all
        of the previous existing ones. Smoothing is done in place.
      - Any SIC Image Variable that is not a built-in buffer in IMAGER.
      - A GILDAS data file

For the two later cases, the Result argument indicates where the smoothed data cube is stored. Result can be a file name or an existing SIC variable of adequate dimensions.

By default, the smoothing does not modify the spectral sampling of the cubes. While this naturally occurs when the smoothing number Nc is odd, the Nc even case requires a specific handling. For Nc even, the smoothed channel at channel "i" sums up half of channel i-Nc/2, half of channels i+Nc/2 and all channels in between. Thus for Nc=2, this is a Hanning smoothing.

Like for UV_SMOOTH, this behaviour can be modified by option /ASYMMETRIC.