Help

To get help about a parameter enter ?. Usually, this will give access to the help-library information for that parameter, for example,

     BOX - Smoothing box size /3,3/ > ?

     BLOCK

       Parameters

         BOX() = _INTEGER (Read)
            The sizes (in pixels) of the rectangular box to be applied to 
            smooth the data.  These should be given in axis order.  A value
            set to 1 indicates no smoothing along that axis.  Thus, for
            example, BOX=[3,3,1] for a three-dimensional NDF would apply a 
            3x3-pixel filter to all its planes independently.
   
            If fewer values are supplied than the number of dimensions of
            the NDF, then the final value will be duplicated for the
            missing dimensions.
   
            The values given will be rounded up to positive odd integers, if
            necessary, to retain symmetry.

     BOX - Smoothing box size /3,3/ >

and then immediately reprompt you for the parameter. There are occasions when information about the parameter is insufficient; you may require to examine the examples or the description of related parameters. This can be achieved by entering ?? to the prompt. You can then delve anywhere in the help information. When you exit the help system you're reprompted for the parameter.