1 /* Copyright (c) 1982 Regents of the University of California */ 2 3 static char sccsid[] = "@(#)ATAN.c 1.2 01/09/89"; 4 5 #include <math.h> 6 extern int errno; 7 8 double 9 ATAN(value) 10 double value; 11 { 12 double result; 13 14 errno = 0; 15 result = atan(value); 16 if (errno != 0) { 17 ERROR("Argument %e is out of the domain of atan\n", value); 18 } 19 return result; 20 } 21