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Dieses Dokument verwendet PHP-Handbuch für chinesische Websites Freigeben
(PHP 4, PHP 5)
acos — 反余弦
$arg
)
返回 arg
的反余弦值,单位是弧度。 acos()
是 cos() 的反函数,它的意思是在
acos() 范围里的每个值都是
a==cos(acos(a)) 。
arg
要处理的参数
arg
的反余弦弧度。
[#1] zoltan dot szentesi at nokia dot com [2006-08-06 03:29:46]
Wondering what is the use of 'acos' function?
It is essential in games, animations and drawings to determine the location of two objects relating to each other.
To the point: the angle of two vectors is calculated by
v1X*v2X + v1Y*v2Y
acos(--------------------------)=angle between two vectors.
|v1| * |v2|
|v1| and |v2| are the length of the vectors and calculated using Pithagoras-formula: |v1|=sqrt(v1X*v1X + v1Y*v1Y)
This helped me to calculate and share given space for 'n' amount of objects so that they don't overlap.
Enjoy! :-)