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.

The arguments to the SUBSTR function are as follows:

matrix

is a character matrix or quoted literal.

position

is a numeric matrix or scalar that contains the starting position.

length

is a numeric matrix or scalar that contains the length of the substring.

Each substring is constructed by 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

The following statements return the output shown:

   B = {abc def ghi, jkl mno pqr};
   a = substr(b, 3, 2);

           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.