SUBSTR Function
takes substrings of matrix elements
 SUBSTR( matrix, position<, length>)
The inputs to the SUBSTR function are as follows:
 matrix
 is a character matrix or quoted literal.
 position
 is a numeric matrix or scalar giving the starting position.
 length
 is a numeric matrix or scalar giving the length of the substring.
The SUBSTR function takes a character matrix as an argument
along with starting positions and lengths and produces a
character matrix with the same dimensions as the argument.
Elements of the result matrix are substrings
of the corresponding argument elements.
Each substring is constructed using
the starting position supplied.
If a length is supplied, this
length is the length of the substring.
If no length is supplied, the remainder
of the argument string is the substring.
The position and length
arguments can be scalars or numeric matrices.
If position or length is a matrix, its dimensions must
be the same as the dimensions of the argument matrix or submatrix.
If either one is a matrix, its values are applied to the
substringing of the corresponding elements of the matrix.
If length is supplied, the element length of the result is
MAX(length); otherwise, the element length of the result is

NLENG( matrix)  MIN( position) + 1 .
The statements
B={abc def ghi, jkl mno pqr};
a=substr(b,3,2);
return the matrix
A 2 rows 3 cols (character, size 2)
C F I
L O R
The element size of the result is 2;
the elements are padded with blanks.
Copyright © 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.