$name = numeric_expressionwhere "numeric_expression" is a number, math command, or other variable. Valid examples are;
$a = 3.6 $b = $a $c = { pi $a add }A variable name can be up to 16 characters in length, composed of letters a through z, numbers 0 through 9, and the underscore, in any combination. Variable names are not case sensitive.
There are several variables that are defined by plotl as it executes scripts. For example, $xdim is the length of the x-axis in inches. A complete listing of variables defined can be obtained by issuing the dumpvariables command.