Name:         GRCTOI

Purpose:      convert character string to integer

Category:     GRAPHICS

File:         pgplot.src

Author:       T.J. Pearson

Use:          see description below.

Description:

            INTEGER FUNCTION GRCTOI (S, I)
            CHARACTER*(*) S
            INTEGER I
      
       GRCTOI: attempt to read an integer from a character string, and return
       the result. No attempt is made to avoid integer overflow. A valid 
       integer is any sequence of decimal digits.
      
       Returns:
        GRCTOI           : the value of the integer; if the first character
                          read is not a decimal digit, the value returned
                          is zero.
       Arguments:
        S      (input)  : character string to be parsed.
        I      (in/out) : on input, I is the index of the first character
                          in S to be examined; on output, either it points
                          to the next character after a valid integer, or
                          it is equal to LEN(S)+1.
      

Updates:      Oct 16, 1998: JPT automatically extracted from source.