是否有可用于计算R中的大因子的包或技术？

Question

如果我计算factorial(100)然后我得到答案[1] 9.332622e+157但是当我尝试计算更大的阶乘时,说factorial(1000)我得到答案[1] Inf

有没有办法在计算阶乘时使用任意精度,以便我可以计算说factorial(1000000)？

Answer 1

对于任意精度,您可以使用gmp或Rmpfr.对于具体阶乘gmp报价factorialZ和Rmpfr拥有factorialMpfr.所以你可以运行类似下面的东西

> Rmpfr::factorialMpfr(200)
1 'mpfr' number of precision  1246   bits 
[1] 788657867364790503552363213932185062295135977687173263294742533244359449963403342920304284011984623904177212138919638830257642790242637105061926624952829931113462857270763317237396988943922445621451664240254033291864131227428294853277524242407573903240321257405579568660226031904170324062351700858796178922222789623703897374720000000000000000000000000000000000000000000000000
> gmp::factorialZ(200)
Big Integer ('bigz') :
[1] 788657867364790503552363213932185062295135977687173263294742533244359449963403342920304284011984623904177212138919638830257642790242637105061926624952829931113462857270763317237396988943922445621451664240254033291864131227428294853277524242407573903240321257405579568660226031904170324062351700858796178922222789623703897374720000000000000000000000000000000000000000000000000

HTH