Zilog Z8F0130 - Manual (Page 457)

UM013037-1212 atan2
Zilog Developer Studio II – Z8 Encore!
User Manual
433
atan2
Computes the principal value of the arc tangent of y/x, using the signs of both arguments
to determine the quadrant of the return value. A domain error occurs if both arguments are
zero.
Synopsis
#include

double atan2(double y, double x);
Returns
The arc tangent of y/x, in the range [-pi, +pi].
Example
double y=.1234;

double x=.4321;

double z;

z=atan2(y,x);
atof
Converts the string pointed to by nptr to double representation. Except for the behavior on
error,
atof is equivalent to strtod (nptr, (char **)NULL) .
Synopsis
#include

double atof(char *nptr);
Returns
The converted value.
Example
char str []="1.234";

double x;

x= atof(str);
atoi
Converts the string pointed to by nptr to int representation. Except for the behavior on
error, it is equivalent to
(int)strtol(nptr, (char **)NULL, 10) .