> x=runif(10,-1,1)
> x
[1] -0.826434863 -0.682567422  0.663395870  0.341920905  0.975422718
[6] -0.004661798 -0.113293662  0.669064062 -0.227924711 -0.787234876
> group=ifelse(x>0,"1","0")
> group
[1] "0" "0" "1" "1" "1" "0" "0" "1" "0" "0"

用 cut(vec, breaks=c(...))

非常感謝你

我少說了一個條件，就是例如，你的分組，前兩個0是一組，後面三個1是一組，可是接下來我要對不同的組求組內均值和組內range，這個要怎麼弄？

再次感謝

> x=runif(10,-1,1)
> x
[1] -0.8645572 -0.6380527 -0.2739525  0.2951239  0.7972818  0.4300227
[7]  0.7396441 -0.1908709  0.4193186 -0.4487091
> group=ifelse(x>0,"1","0")
> group
[1] "0" "0" "0" "1" "1" "1" "1" "0" "1" "0"
> split(x,group)
$`0`
[1] -0.8645572 -0.6380527 -0.2739525 -0.1908709 -0.4487091

$`1`
[1] 0.2951239 0.7972818 0.4300227 0.7396441 0.4193186

> lapply(split(x,group),mean)
$`0`
[1] -0.4832285

$`1`
[1] 0.5362782

> x=runif(10,-1,1)
> x
[1] -0.8645572 -0.6380527 -0.2739525  0.2951239  0.7972818  0.4300227
[7]  0.7396441 -0.1908709  0.4193186 -0.4487091
> group=ifelse(x>0,"1","0")
> group
[1] "0" "0" "0" "1" "1" "1" "1" "0" "1" "0"
> split(x,group)
$`0`
[1] -0.8645572 -0.6380527 -0.2739525 -0.1908709 -0.4487091

$`1`
[1] 0.2951239 0.7972818 0.4300227 0.7396441 0.4193186

> lapply(split(x,group),mean)
$`0`
[1] -0.4832285

$`1`
[1] 0.5362782