kotlin-stdlib / kotlin.math / atan2

atan2

Common
JVM
JS
Native
1.2
fun atan2(y: Double, x: Double): Double
(Common source) (JVM source) (JS source) (Native source)
fun atan2(y: Float, x: Float): Float
(Common source) (JVM source) (JS source) (Native source)

Returns the angle theta of the polar coordinates (r, theta) that correspond to the rectangular coordinates (x, y) by computing the arc tangent of the value y / x; the returned value is an angle in the range from -PI to PI radians.

Special cases:

  • atan2(0.0, 0.0) is 0.0
  • atan2(0.0, x) is 0.0 for x > 0 and PI for x < 0
  • atan2(-0.0, x) is -0.0 for 'x > 0 and -PI for x < 0`
  • atan2(y, +Inf) is 0.0 for 0 < y < +Inf and -0.0 for '-Inf < y < 0`
  • atan2(y, -Inf) is PI for 0 < y < +Inf and -PI for -Inf < y < 0
  • atan2(y, 0.0) is PI/2 for y > 0 and -PI/2 for y < 0
  • atan2(+Inf, x) is PI/2 for finite xy
  • atan2(-Inf, x) is -PI/2 for finite x
  • atan2(NaN, x) and atan2(y, NaN) is NaN