在用
Matlab绘制各种常用概率分布的密度函数时，都比较简单，唯独超几何分布试了几次都不成功，输出结果总是
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Zo i\r 10 D6fkjf 查看了一下帮助 help hygepdf
X/D^?BKC .9Y,N&V<H HYGEPDF Hypergeometric probability density function.
| <q9Ee K3Wh F Y = HYGEPDF(X,M,K,N) returns the hypergeometric probability
T .57Okp density function at X with integer parameters M, K, and N.
Gc'CS_L Note: The density function is zero unless X is an integer.
]S=AO/' |QI FtdU5T The size of Y is the common size of the input arguments. A scalar input
w>q:&Q functions as a constant matrix of the same size as the other inputs.
#s-^4znv9 W _ = See also hygecdf, hygeinv, hygernd, hygestat, pdf.
N4wv'OrL] xp4w9.X 5( Reference page in Help browser
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w^1! 超几何分布参数较多，这里关于三个参数的指代不详。又在互联网上查了相关资料，包括该函数的定义式：
EMV< PshW= r[TTG0| http://ccpublic-1.central.cranfield.ac.uk/2001DMSOMFRC/pr062320/Matlab/stats/hygepdf.m \VTNXEw*G G q" [5r" 直到发现这个例子后才清楚各个参数所代表的具体意义。
NPL(5 @ 2'38(wXn# Suppose you have a lot of 100 floppy disks and you know that 20 of them are defective. What is the probability of drawing 0 through 5 defective floppy disks if you select 10 at random?
&s|a\!>l k [6xuyY] p = hygepdf(0:5,100,20,10)
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q&`$ p = 0.0951 0.2679 0.3182 0.2092 0.0841 0.0215
.5;X d? eoC@b/F4 详细可参见：
7HpfHqJ7 http://www.physnet.uni-hamburg.de/physnet/matlab/help/toolbox/stats/hygepdf.html#4257 ,1s ,G]%M ;-OnCLr 果然与一般对超几何分布公式字母惯常表示方式有所不同。尝试将上述分布作图如下
F>0[v|LG bvuoo/ x = 0:5
4|Wg lri p = hygepdf(x,100,20,10);
}nQni? plot(x,p,':k*')
