两个可变循环“for”以正确的顺序输出(two variable loop “for” output in the right sequence)

两个可变循环“for”以正确的顺序输出(two variable loop “for” output in the right sequence)

我怎样才能使这个循环，以与数据框（a，b）相同的顺序出现。

a <- seq(1,36,2) b <- seq(2,36,2) c <- NULL for (i in a) { for (j in b) { d <- cbind(i, j) c <- rbind(c,d) } } c

输出c以我想要的顺序给出j ，但是我每18次重复一次。

这是我想要的方式

data.frame(a,b)

How can I make this loop, appearing in the same sequence as dataframe(a,b).

a <- seq(1,36,2) b <- seq(2,36,2) c <- NULL for (i in a) { for (j in b) { d <- cbind(i, j) c <- rbind(c,d) } } c

The output c gives j in the order I want, but i repeats itself every 18 times.

This is the way I want it

data.frame(a,b)

最满意答案

你不需要两个循环，只需要一个循环。

a <- seq(1,36,2) b <- seq(2,36,2) c <- NULL for(i in 1:length(a)){ d<-cbind(a[i],b[i]) c<-rbind(c,d) }

You don't need two loops, just one.

a <- seq(1,36,2) b <- seq(2,36,2) c <- NULL for(i in 1:length(a)){ d<-cbind(a[i],b[i]) c<-rbind(c,d) }