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        [GREG2\]RGDATA  [Name|Array_X Array_Y Array_Z]  [/SUBSET NXmin NYmin
    NXmax NYmax] [/VARIABLE] [/FORMAT Fmt  [code]]  [/INCREMENT  IncX  IncY]
    [/BLANKING Bval]

    This  command  optionally creates, then loads a two-dimensional map into
    the Regular Grid array (to be contoured by RGMAP, plotted  by  PLOT...).
    This is THE basic command needed for subsequent 2-dimensional treatment.
    "Regular Grid" means that data is internally stored as a two-dimensional
    array,  thus  lies on a Regularly sampled Grid. The user-provided "pixel
    values" may come from various "descriptions" of such  regularly  sampled
    (but possibly uncompletely sampled) data:
       1) Three  1-dimensional arrays, say, X Y and Z, that contain Z=f(X,Y)
        at regular intervals in X and Y.
       2) A preexisting internal 2-D array (possibly a section of a 3D or 4D
       3) An external, specially formatted, file.

    For  data  NOT  REGULARLY ("randomly") sampled, use the GREG2\RANDOM_MAP
    command instead. The Regular Grid is itself a 2D SIC variable under  the
    name  "RG".  Once loaded, the RG can be saved on a file with the command

    The following command syntax is used to deduce  which  "description"  is
      - Without arguments following the command, or with 3 arguments, RGDATA
        will try to assemble Z=f(X,Y) either form the X,Y and Z  arrays  (as
        defined  by  command COLUMN) or from "Array_X Array_Y Array_Z", that
        should be 1D SIC variables previously created by command SIC\DEFINE.
        The option /INCREMENT is used to force the X and Y sampling interval
        to (IncX,IncY) in case of roundoff errors. If a  blanking  value  is
        currently defined, non-sampled pixels will be attributed this value,
        which is overriden by the Bval value of the /BLANKING  option.  Note
        that,  if  a blanking value is currently defined, pixels for which X
        or Y are in the blanking range are themselves blanked.
      - With ONE argument (Name) following the command, Name is taken as the
        name  of an existing SIC 2D variable if option /VARIABLE is present.
        Otherwise, Name  is  a  specially  formatted  file  (see  HELP RGDA-
        TA FILE_FORMAT) from which the Regular Grid array must be read in.
    A  rectangular  SUBSET of the array, defined by the pixel coordinates of
    the Bottom Left Corner and Top Right Corner can be selected.  RGDATA al-
    locates  virtual  memory  according to the map size, so that there is no
    limit on the array dimensions.


Gildas manager 2014-07-01