ATN2

ATN2

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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

 

 

atn2

 

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

RAD2DEG , DEG2RAD , COS , SIN , TAN , ATN

 

 

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