Valid
GTL expressions are identical to valid WHERE expressions. See the
WHERE statement documentation in Base SAS for a comprehensive list
of operators and operands. However, GTL expressions do not perform
subset operations as WHERE expressions do. The major difference in
the result of a logical GTL expression on a column is that a Boolean
value is returned for each observation without changing the number
of observations.
For example,
in the following line of code, the expression for the Y= argument
does not reduce the number of observations plotted.
scatterplot x=name y=eval(height between 40 and 60);
Instead,
the computed numeric column for the Y= argument consists of 0s and 1s,
based on whether each observation’s HEIGHT value is between
40 and 60. Whenever expressions are used to create new columns, a
new column name is internally manufactured so it does not collide
with other columns in use.