﻿ ATN2
 ATN2

Action

ATN2 is a four-quadrant arc-tangent.

While the ATN-function returns from -p/2 (-90°) to p/2 (90°), the ATN2 function returns the whole range of a circle from -p (-180°) to +p (180°). The result depends on the ratio of Y/X and the signs of X and Y.

Syntax

var = ATN2( y, x )

Remarks

 Var A floating point variable that is assigned with the ATN2 of variable y and x. X The float variable with the distance in x-direction. Y The float variable with the distance in y-direction

 Quadrant Sign Y Sign X ATN2 I + + 0 to p/2 II + - p/2 to p III - - -p/2 to -p IV - + 0 to –p/2

If you go with the ratio Y/X into ATN you will get same result for X greater zero (right side in coordinate system) as with ATN2. ATN2 uses X and Y and can give information of the angle of the point over 360° in the coordinates system.

All trig functions work with radians. Use deg2rad and rad2deg to convert between radians and angles.

See Also

Example

\$regfile = "m48def.dat"                                   ' specify the used micro

\$crystal = 8000000                                         ' used crystal frequency

\$baud = 19200                                               ' use baud rate

\$hwstack = 32                                               ' default use 32 for the hardware stack

\$swstack = 10                                               ' default use 10 for the SW stack

\$framesize = 40                                             ' default use 40 for the frame space

Config Com1 = Dummy , Synchrone = 0 , Parity = None , Stopbits = 1 , Databits = 8 , Clockpol = 0

Dim S As Single , X As Single

X = 0.5 : S = 1.1

S = Atn2(s , X)

Print S ' prints 1.144164676

End