Java Utililty Methods atan2

double atan2(double arg1, double arg2)
atan

if (arg1 + arg2 == arg1) {
 if (arg1 >= 0) {
 return PIO2;
 return -PIO2;
arg1 = atan(arg1 / arg2);
if (arg2 < 0) {
...

double atan2(double x, double y)
Approximates the atan2 function.

if (y == 0.0 && x == 0.0) {
 return 0.0;
} else if (x > 0.0) {
 if (y > 0.0) { 
 return atan(y / x);
 } else { 
 return 2 * Math.PI - atan(-y / x);
} else if (x < 0.0) {
 if (y < 0.0) { 
 return Math.PI + atan(y / x);
 } else { 
 return Math.PI - atan(-y / x);
} else if (y < 0.0) { 
 return 2 * Math.PI - Math.PI / 2.;
} else {
 return Math.PI / 2.;

double atan2(double y, double x)
Converts rectangular coordinates (x, y) to polar (r, theta).

return Math.atan2(y, x);

double atan2(double y, double x)
Converts rectangular coordinates (x, y) to polar (r, theta).

double pi_o_4 = 7.8539816339744827900E-01; 
double pi_o_2 = 1.5707963267948965580E+00; 
double pi = 3.1415926535897931160E+00; 
double pi_lo = 1.2246467991473531772E-16; 
double z;
int k, m;
long hx = Double.doubleToLongBits(x);
long hy = Double.doubleToLongBits(y);
...

double atan2(double y, double x)
atan

if (y == 0. && x == 0.)
 return 0.;
if (x > 0.)
 return atan(y / x);
if (x < 0.) {
 if (y < 0.)
 return -(Math.PI - atan(y / x));
 else
...

double atan2(double y, double x)
atan

double atn = atan(y / x);
if (y >= 0) {
 if (x >= 0)
 return atn;
 return Math.PI + atn;
if (x >= 0) {
 return atn;
...

double[] atan2(double[] arr1, double[] arr2)
atan

double[] result = new double[arr1.length];
for (int i = 0; i < arr1.length; i++) {
 result[i] = Math.atan2(arr2[i], arr1[i]);
return result;

double atan2(final double y, final double x)
atan

return StrictMath.atan2(y, x);

float atan2(float y, float x)
Returns atan2 in radians, faster but less accurate than Math.atan2.

if (x == 0f) {
 if (y > 0f)
 return PI / 2;
 if (y == 0f)
 return 0f;
 return -PI / 2;
final float atan, z = y / x;
...

double atan2(Integer y, Integer x)
atan

return Math.atan2(y.doubleValue(), x.doubleValue());