查看“LlAtan2”的源代码

{{LSL Header|ml=*}}{{LSLC|Keywords}}{{LSLC|Flow Control}}{{LSLC|}}


{{函数详情
|函数名=float llAtan2( float y, float x );
|参数= 返回y，x的arctangent2浮点值。
|返回值= •浮动y
•浮动x
与反正切（y/x）类似，只是它利用x&amp;y的符号来确定象限并避免被零除。

|注意事项=
如果x是正零并且。。。
y为零，返回零。
y为正，返回PI/2。
y为负，-PI/2被返回。
如果x是负零并且。。。
y为正零，返回PI。
y为负零，-PI返回。
y为正，返回PI/2。
y为负，-PI/2被返回。
或者
如果（（字符串）x！=（字符串）0.0&amp;&amp;y==0.0）//负零
返回PI*~-2*（（字符串）y！=（字符串）0.0）；
返回（（y>0）-（y<0））*PI_乘以2；
返回值在范围[-PI，PI]
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|示例=
示例1
<pre> 
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));
  }
}
//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);

}
</pre>



|相关函数=
[[llSin]][[llAsin]]–	sine & inverse Sine
[[ llCos]][[llAcos]]–	cosine & inverse cosine
[[llTan	]]	   –  tangent
文献：
[https://en.wikipedia.org/wiki/Atan2][https://en.wikipedia.org/wiki/Inverse_trigonometric_functions]
|相关事件=[[Search JIRA for related Issues]]
}}