ATN2( ) Function
Returns the arc tangent in all four quadrants from specified values.
ATN2(nYCoordinate, nXCoordinate)
Return Value
Numeric
Parameters
nYCoordinate
Specifies the y coordinate.nXCoordinate
Specifies the x coordinate.
Remarks
ATN2( ) returns the angle (in radians) between the line y = 0 and the line connecting the specified coordinates and the origin (0, 0) of the coordinate system.
ATN2( ) returns a value between – pi/2 and +pi/2.
You can convert the value returned by ATN2( ) to degrees with RTOD( ). You can specify the number of decimal places that are displayed in the result with SET DECIMALS.
Example
CLEAR
? PI( ) && Displays 3.14
? ATN2(0,-1) && Displays 3.14
STORE COS(PI( )) TO gnXCoord
STORE SIN(PI( )) TO gnYCoord
? ATN2(gnYCoord,gnXCoord) && Displays 3.14
? ATN2(gnYCoord,gnXCoord)/PI( ) && Displays 1.00