The function atan2 ⁡ ( y , x ) {\displaystyle \operatorname {atan2} (y,x)} (from "2-argument arctangent") is defined as the angle in the Euclidean plane, given in radians, between the positive x {\displaystyle x} axis and the ray from the origin to the point ( x , y ) {\displaystyle (x,\,y)} .