atan2(y,x)
atan2(y,I)
atan2(J,x)
atan2(J,I)
i1 : atan2(1,0) o1 = 1.5707963267949 o1 : RR (of precision 53)
i2 : atan2(0,1) o2 = 0 o2 : RR (of precision 53)
i3 : atan2(-1,-1) o3 = -2.35619449019234 o3 : RR (of precision 53)
The object atan2 is a method function.