Overview

In GTL, as in Base SAS, an expression is an arithmetic or logical expression that consists of a sequence of operators, operands, and functions. An operand is a dynamic, a macro variable, a column, a function, or a constant. An operator is a symbol that requests a comparison, logical operation, or arithmetic calculation. In GTL, the expression must be enclosed in EVAL.

Expressions can be used set an option value that is

a constant
a column
part of the text for ENTRYTITLE, ENTRYFOOTNOTE, and ENTRY statements.

Example of computing constants:

/* create reference lines at computed positions */ 
referenceline y=eval(mean(height)+2*std(height)) /
  curvelabel="+2 STD";
referenceline y=eval(mean(height));
referenceline y=eval(mean(height)-2*std(height)) /
  curvelabel="-2 STD";

Example of creating a new column:

/* create a new column as a log transformation */
scatterplot x=date y=eval(log10(amount));

Example of building a text string:

/* create a date and time stamp as a footnote */
entryfootnote  eval(put(today(),date9.)||" : "||
  put(time(),timeampm8.));