- Form: PARAMETER [varname] [varname] [STRING=string_var] ...
-
PARAMETER evaluate parameters passed to a procedure. An example will show
best how PARAMETER works. Suppose the following command was typed:
The parameter list portion of the command line is saved, i.e. '2 X
IMAGEFILE'. The procedure TEST.PRO is then called. TEST has in it the
command
- PARAMETER BUFNUM FACTOR STRING=FILENAME
BUFNUM and FACTOR are taken to be variable names and are associated with
the first two parameters from the parameter list. In effect it does the
command SET BUFNUM=2 FACTOR=X. Note that '2' and 'X' could have been any
arithmetic expression.
The STRING= keyword means that the third parameter is used as a literal
string and the string variable name FILENAME is given the string value
IMAGENAME, in effect doing the command:
- STRING FILENAME IMAGENAME
If there are fewer parameters in the CALL than required in the PARAMETER
command, the missing parameters are taken to be 0 or blank, as appropriate.
Note that there is only one area in VISTA for saving the list of passed
parameters, so the PARAMETER command should be executed before calling
another procedure.