atan517

#include <80c517.h>

float atan517 (
  float x);      /* number to calculate arc tangent of */

The atan517 function calculates the arc tangent of the floating-point number x.

Note

• This routine uses the arithmetic unit of the Infineon C517x/C509 to provide accelerated execution speed. Do not use this routine with a CPU that does not support this feature.

The atan517 function returns the arc tangent of x.

For x ∈ (-∞, ∞), atan517(x) → (-π/2, π/2).
For x = NaN, atan517(x) → NaN.
For x = ±INF, atan517(x) → ±π/2.

acos, acos517, asin, asin517, atan, atan2

#include <80c517.h>
#include <stdio.h> /* for printf */

void tst_atan (void) {
  float x;
  float y;

  for (x = -10.0; x <= 10.0; x += 0.1) {
    y = atan517 (x);
    printf ("ATAN517(%f) = %f\n", x, y);
  }
}