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
e?07o!7[; ^!k_"C)B ans =
'Pn:10; -AVT+RE9z NaN
YKayaI\* .-MJ5 d: 查看了一下帮助 help hygepdf
$I#~<bW, 32anmVnf HYGEPDF Hypergeometric probability density function.
?aBAmyxm =F/ R*5:T Y = HYGEPDF(X,M,K,N) returns the hypergeometric probability
;$$w`LyP density function at X with integer parameters M, K, and N.
|d6/gSiF Note: The density function is zero unless X is an integer.
##F$8d )q /RhM6N The size of Y is the common size of the input arguments. A scalar input
RhF< {U. functions as a constant matrix of the same size as the other inputs.
KMfRMc& l6xqc,h!K See also hygecdf, hygeinv, hygernd, hygestat, pdf.
'zMmJl}\vd l9+CJAmq Reference page in Help browser
#_3-(H5u doc hygepdf
yEJ3O^(F VB8eGMo 超几何分布参数较多，这里关于三个参数的指代不详。又在互联网上查了相关资料，包括该函数的定义式：
l$l6,OzS@ 6fBA #Kb http://ccpublic-1.central.cranfield.ac.uk/2001DMSOMFRC/pr062320/Matlab/stats/hygepdf.m F`,bFQ 7OXRR)]V 直到发现这个例子后才清楚各个参数所代表的具体意义。
3]'h (C 6wq%4RI0 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?
vKdS1Dn1 i^IL o,Q p = hygepdf(0:5,100,20,10)
oHS Di P&Xy6@%[Z p = 0.0951 0.2679 0.3182 0.2092 0.0841 0.0215
|@R/JGB^ =Bh,>Kg 详细可参见：
v!<FeL W http://www.physnet.uni-hamburg.de/physnet/matlab/help/toolbox/stats/hygepdf.html#4257 3y:),;|5 ]eFNR1<OP 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
*(i %\ KqaEHL x = 0:5
r"x}=# b! p = hygepdf(x,100,20,10);
7+[L6q/K plot(x,p,':k*')
