atan function and atan2 function

Atan function: Portal.

atan2 function: Portal.

Atan and atan2 are all seeking the inverse tangent function, such as: There are two points (x1,y1), and Point (X2,y2);

Then the angle calculation method of the slope formed by these two points is:

float angle = Atan ((y2-y1)/(X2-X1));

Or

float angle = atan2 (y2-y1, x2-x1);

The range of domains is different, atan:+-π/2,atan2:+-π

Atan and atan2 differences:

1: The parameters are filled in different ways;

The advantage of 2:atan2 is that if x2-x1 equals 0 can still be calculated, but the Atan function will cause the program error;

It is recommended to use the ATAN2 function.

atan function and atan2 function