Difference between revisions of "LlAtan2"

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Function: float llAtan2( float y, float x );
 3 Function ID 0 Forced Delay 10 Energy

Returns a float that is the arctangent2 of y, x.

 • float y • float x

Similar to the arctangent(y/x) except it utilizes the signs of x & y to determine the quadrant. Returns zero if x and y are zero.

Examples

<lsl>default {

``` state_entry()
{
float num1 = llFrand(100.0);
float num2 = llFrand(100.0);
```
```   llOwnerSay("y = " + (string)num1);
llOwnerSay("x = " + (string)num2);
```
```   llOwnerSay("The arctangent of y divided by x is " + (string)llAtan2(num1, num2));
}
```

}</lsl><lsl>//Function with input of a vector determining the position of a target and returning //a string with the literal compass-direction of that target towards your position //by Ramana Sweetwater 2009/01, any use allowed license :-)

string compass (vector target) {

```   vector me = llGetPos();
float distance = llVecDist(me, target);
list DIRS =["W","NW","N","NE","E","SE","S","SW","W"];
return llList2String(DIRS,llCeil(4.5-((4*llAtan2((target.y-me.y)/distance,(target.x-me.x)/distance))/PI)));
```
}</lsl>

Functions

 • llSin llAsin – sine & inverse Sine • llCos llAcos – cosine & inverse cosine • llTan – tangent

Articles

 • Wikipedia:Atan2 • Wikipedia:Inverse_trigonometric_function

Deep Notes

Signature

```function float llAtan2( float y, float x );
```