R中fisher 检验FEXACT error 6. LDKEY=621 is too small for this problem问题

问题：

> obs
     [,1] [,2] [,3]
[1,]   83   29   35
[2,]   30   20   10
[3,]   23   12    1
[4,]   11   13    0
> fisher.test(obs)
Error in fisher.test(obs) : 
  FEXACT error 6.  LDKEY=621 is too small for this problem,
  (ii := key2[itp=394] = 488497, ldstp=18630)
Try increasing the size of the workspace and possibly 'mult'

原来是我的workspace 太小，增加workspace ：

> fisher.test(obs,workspace = 2e7)

	Fisher's Exact Test for Count Data

data:  obs
p-value = 0.0002342
alternative hypothesis: two.sided

有的时候数据太多，可能花费很长时间，可以加参数simulate.p.values=TRUE，可以节省时间。