x = 1111111234.6547389758965789345 y = formatC(x, digits = 8, format = "f") # [1] "1111111234.65473890"
format(100000000/1000, scientific=FALSE)
REF:
https://www.r-bloggers.com/number-formatting/
https://stackoverflow.com/questions/3443687/formatting-decimal-places-in-r
https://stat.ethz.ch/R-manual/R-devel/library/base/html/formatc.html
原文：http://www.cnblogs.com/emanlee/p/7573594.html