replaces substrings in each entry of a given matrix

The inputs to the RSUBSTR subroutine are as follows:

is any character matrix.

is an matrix or a scalar that determines the starting positions for substrings to be replaced.

is an matrix or a scalar that determines the lengths of substrings to be replaced.

is an matrix or a scalar that specifies the replacement strings.

The RSUBSTR function returns an matrix with substrings replaced. It replaces or substitutes substrings of the input matrix with new strings. If is zero, the replacement string in is simply inserted into the input matrix at the position indicated by .

For example, the following statements replace the first two characters of each entry in the matrix X with the corresponding entry in the matrix R:

   proc iml;
      x = {abc def ghi,jkl mno pqr};
      r = {z y x, w v u};
      p = 1;
      l = 2;
      c=rsubstr(x,p,l,r);
      print x;
      print c;