betarnd  贝塔分布的随机数生成器
binornd  二项分布的随机数生成器
chi2rnd  卡方分布的随机数生成器
exprnd  指数分布的随机数生成器
frnd  F分布的随机数生成器
gamrnd  伽玛分布的随机数生成器
geornd  几何分布的随机数生成器
hygernd  超几何分布的随机数生成器
lognrnd  对数正态分布的随机数生成器
nbinrnd  负二项分布的随机数生成器
ncfrnd  非中心f分布的随机数生成器
nctrnd  非中心t分布的随机数生成器
ncx2rnd  非中心卡方分布的随机数生成器
normrnd  正态（高斯）分布的随机数生成器
pois-s-rnd  泊松分布的随机数生成器
raylrnd  瑞利分布的随机数生成器
trnd  学生氏t分布的随机数生成器
unidrnd  离散均匀分布的随机数生成器
unifrnd  连续均匀分布的随机数生成器
weibrnd  威布尔分布的随机数生成器

RANDN  Normally distributed random numbers.

RANDOM Generate random arrays from a specified distribution.
    R = RANDOM(NAME,A) returns an array of random numbers chosen from the
    one-parameter probability distribution specified by NAME with parameter
    values A.
    R = RANDOM(NAME,A,B) or R = RANDOM(NAME,A,B,C) returns an array of random
    numbers chosen from a two- or three-parameter probability distribution
    with parameter values A, B (and C).
    The size of R is the common size of the input arguments.  A scalar input
    functions as a constant matrix of the same size as the other inputs.
    R = RANDOM(NAME,A,M,N,...) or R = RANDOM(NAME,A,[M,N,...]) returns an
    M-by-N-by-... array of random numbers for a one-parameter distribution.
    Similarly, R = RANDOM(NAME,A,B,M,N,...) or R = RANDOM(NAME,A,B,[M,N,...]),
    and R = RANDOM(NAME,A,B,C,M,N,...) or R = RANDOM(NAME,A,B,C,[M,N,...]),
    return an M-by-N-by-... array of random numbers for a two- or
    three-parameter distribution.
    NAME can be:
       \'beta\'  or \'Beta\',
       \'bino\'  or \'Binomial\',
       \'chi2\'  or \'Chisquare\',
       \'exp\'   or \'Exponential\',
       \'ev\'    or \'Extreme Value\',
       \'f\'     or \'F\',
       \'gam\'   or \'Gamma\',
       \'gev\'   or \'Generalized Extreme Value\',
       \'gp\'    or \'Generalized Pareto\',
       \'geo\'   or \'Geometric\',
       \'hyge\'  or \'Hypergeometric\',
       \'logn\'  or \'Lognormal\',
       \'nbin\'  or \'Negative Binomial\',
       \'ncf\'   or \'Noncentral F\',
       \'nct\'   or \'Noncentral t\',
       \'ncx2\'  or \'Noncentral Chi-square\',
       \'norm\'  or \'Normal\',
       \'poiss\' or \'Poisson\',
       \'rayl\'  or \'Rayleigh\',
       \'t\'     or \'T\',
       \'unif\'  or \'Uniform\',
       \'unid\'  or \'Discrete Uniform\',
       \'wbl\'   or \'Weibull\'.

from: http://blog.sciencenet.cn/home.php?mod=space&uid=388372&do=blog&id=403448