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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BMbZ34^e HO8x: 2m 查看了一下帮助 help hygepdf
K./L'Me ;MKfssG HYGEPDF Hypergeometric probability density function.
+& )&Ny$W =/^{Pn Y = HYGEPDF(X,M,K,N) returns the hypergeometric probability
[iG4 qI density function at X with integer parameters M, K, and N.
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(> Note: The density function is zero unless X is an integer.
uI&<H T? n0@ \x=9 The size of Y is the common size of the input arguments. A scalar input
^: V6= functions as a constant matrix of the same size as the other inputs.
nc>Ae`"( *| YR 8f See also hygecdf, hygeinv, hygernd, hygestat, pdf.
@{^6_n+gT% EAnw:yUV( Reference page in Help browser
sJ cwN.s doc hygepdf
(L8z <id<z JclG*/Wjg4 超几何分布参数较多，这里关于三个参数的指代不详。又在互联网上查了相关资料，包括该函数的定义式：
cvv(OkC m"8Gh `Fo http://ccpublic-1.central.cranfield.ac.uk/2001DMSOMFRC/pr062320/Matlab/stats/hygepdf.m E\=23[0 9|LV
x3] 直到发现这个例子后才清楚各个参数所代表的具体意义。
!PY.F nZ RVe UQ% Suppose you have a lot of 100 floppy disks and you know that 20 of them are defective. What is the probability of drawing 0 through 5 defective floppy disks if you select 10 at random?
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p%Q ^U@E rc#d p = hygepdf(0:5,100,20,10)
j[YO1q* b+ v!3| p = 0.0951 0.2679 0.3182 0.2092 0.0841 0.0215
y@Ga9bI7 >_um-w #C 详细可参见：
]$a,/Jt http://www.physnet.uni-hamburg.de/physnet/matlab/help/toolbox/stats/hygepdf.html#4257 %'i`Chc^!; i_qR&X 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
095Z Z20 1W2hd!J7C x = 0:5
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@(AE( p = hygepdf(x,100,20,10);
TY h_uox6 plot(x,p,':k*')
