WorksheetFunction.Atan2 method (Excel)
Returns the arctangent, or inverse tangent, of the specified x- and y-coordinates. The arctangent is the angle from the x-axis to a line containing the origin (0, 0) and a point with coordinates (x_num, y_num). The angle is given in radians between -pi and pi, excluding -pi.
Syntax
expression.Atan2 (Arg1, Arg2)
expression A variable that represents a WorksheetFunction object.
Parameters
Name | Required/Optional | Data type | Description |
---|---|---|---|
Arg1 | Required | Double | The x-coordinate of the point. |
Arg2 | Required | Double | The y-coordinate of the point. |
Return value
Double
Remarks
A positive result represents a counterclockwise angle from the x-axis; a negative result represents a clockwise angle.
The following conditions apply:
Where x > 0 ATAN2(x,y) = ATAN(y/x)
Where y >= 0, x < 0 ATAN2(x,y) = ATAN(y/x)+PI()
Where y < 0, x < 0 ATAN2(x,y) = ATAN(y/x) - PI()
Where y > 0, x = 0 ATAN2(x,y) = PI()/2
Where y < 0, x = 0 ATAN2(x,y) = -PI()/2
If both x and y are 0, Atan2 returns an error value.
To express the arctangent in degrees, multiply the result by 180/PI( ) or use the Degrees method.
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