Difference between revisions of "LlAtan2"
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|return_text=that is the {{wikipedia|Atan2|arctangent2}} of {{LSLP|y}}, {{LSLP|x}}. | |return_text=that is the {{wikipedia|Atan2|arctangent2}} of {{LSLP|y}}, {{LSLP|x}}. | ||
|func_footnote=Similar to the <span class="plainlinks">{{wikipedia|Inverse_trigonometric_functions|arctangent}}</span>({{LSLP|y}}/{{LSLP|x}}) except it utilizes the signs of {{LSLP|x}} & {{LSLP|y}} to determine the quadrant and avoids division by zero. <br /> | |func_footnote=Similar to the <span class="plainlinks">{{wikipedia|Inverse_trigonometric_functions|arctangent}}</span>({{LSLP|y}}/{{LSLP|x}}) except it utilizes the signs of {{LSLP|x}} & {{LSLP|y}} to determine the quadrant and avoids division by zero. <br /> | ||
|spec= | |||
If {{LSLP|x}} is zero and... | If {{LSLP|x}} is zero and... | ||
* {{LSLP|y}} is zero, '''zero''' is returned. | * {{LSLP|y}} is zero, '''zero''' is returned. | ||
| Line 13: | Line 14: | ||
Or <code>(({{LSL Param|y}} > 0) - ({{LSL Param|y}} < 0)) * [[PI_BY_TWO]]</code>.<br /> | Or <code>(({{LSL Param|y}} > 0) - ({{LSL Param|y}} < 0)) * [[PI_BY_TWO]]</code>.<br /> | ||
The returned value is in the range {{Interval|gte=-[[PI]]|gteh=-PI|lte=PI|center=return}}{{Interval/Footnote}}. | The returned value is in the range {{Interval|gte=-[[PI]]|gteh=-PI|lte=PI|center=return}}{{Interval/Footnote}}. | ||
|caveats | |caveats | ||
|constants | |constants | ||
Revision as of 22:15, 6 June 2012
| LSL Portal | Functions | Events | Types | Operators | Constants | Flow Control | Script Library | Categorized Library | Tutorials |
Summary
Function: float llAtan2( float y, float x );| 3 | Function ID |
| 0.0 | Forced Delay |
| 10.0 | 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 and avoids division by zero.
Specification
Caveats
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 :-) //corrected by Patrick Muggins
string compass (vector target) {
vector source = llGetPos(); list DIRS =["W","NW","N","NE","E","SE","S","SW","W"]; integer index = llCeil(3.5 - (4 * llAtan2(target.y - source.y, target.x - source.x) / PI)); return llList2String(DIRS, index);
}</lsl>
/Compass QASee Also
Deep Notes
Footnotes
- ^ The ranges in this article are written in Interval Notation.
Signature |
|---|
function float llAtan2( float y, float x ); |