结合大量的列中的R

Question

我有一个数据组具有以下的列

C1, V1, C2, V2, C3, V3.........C1000, V1000 

所有列的观测（行）相等数目。

如何将上述数据组合成只有C，V列的新数据集，这些列将包含长格式数据集的所有行的行？

Answer 1

您也可以直接使用reshape功能base R.我使用的是相同的例子@Kohske

reshape(d, direction = 'long', varying = 1:NCOL(d), sep = "") 

Answer 2

假设你的专栏真正做到C和V，和当前的数据帧之间交替存储在dat，这样的事情应该工作：

rs <- data.frame(C = unlist(dat[, seq(1,2000,by = 2)]), 
       V = unlist(dat[, seq(2,2000,by = 2)])) 

Answer 3

下面是使用plyr和reshape2包的例子：

> # sample data 
> d <- data.frame(matrix(runif(100), 5, 20)) 
> names(d) <- paste(c("C", "V"), rep(1:10, each = 2), sep = "") 
> d 
     C1   V1  C2  V2   C3  V3   C4   V4  C5   V5  C6  V6   C7  V7   C8 
1 0.1867699 0.93659453 0.1197284 0.9628986 0.52336647 0.9650141 0.651377738 0.90073030 0.2559667 0.91905240 0.3563512 0.6935289 0.43179306 0.6400699 0.61515316 
2 0.7576912 0.30851077 0.8677065 0.4920025 0.51844891 0.1035328 0.338086219 0.49316520 0.2735068 0.31079714 0.7707765 0.7829738 0.18611600 0.4998730 0.31711230 
3 0.8104602 0.51727882 0.4034713 0.4545304 0.07993988 0.3806043 0.361723985 0.91731069 0.7836848 0.51605825 0.1664879 0.9997097 0.60784616 0.7576581 0.07144218 
4 0.6629312 0.78566815 0.3091202 0.6267486 0.04399409 0.5988425 0.001489632 0.15462250 0.6210522 0.51142738 0.2298060 0.8632633 0.01202089 0.6192330 0.61705098 
5 0.3714499 0.03534432 0.1200033 0.5566100 0.15498809 0.7600497 0.668615795 0.07763992 0.1017358 0.07118067 0.4254473 0.5877628 0.20763356 0.7201208 0.56749348 
     V8  C9  V9  C10  V10 
1 0.4997906 0.1539158 0.5079096 0.4153216 0.5391126 
2 0.8372036 0.4995961 0.2236440 0.5060925 0.3148300 
3 0.9487363 0.5366132 0.3454843 0.8130159 0.6747609 
4 0.8924971 0.6801537 0.1349331 0.5654011 0.4541599 
5 0.5704078 0.5948960 0.6172788 0.3661633 0.9945200 
> 
> # load library 
> library(reshape2) 
> library(plyr) 
> 
> # make obs. id 
> d$id <- 1:nrow(d) 
> 
> # melt it to longest format (i.e., 1 obs/1 row) 
> d2 <- melt(d, id = "id") 
> 
> # split label into C/N and number 
> d3 <- mutate(d2, 
+    N = substr(variable, 1, 1), 
+    i = as.integer(substr(variable, 2, 100)), 
+    variable = NULL) 
>    
> # reshape and order the data    
> d4 <- dcast(d3, id+i~N, value_var = "value") 
> d4$id <- NULL 
> id <- arrange(d4, i) 
> head(d4) 
    i   C   V 
1 1 0.1867699 0.9365945 
2 2 0.1197284 0.9628986 
3 3 0.5233665 0.9650141 
4 4 0.6513777 0.9007303 
5 5 0.2559667 0.9190524 
6 6 0.3563512 0.6935289 

Answer 4

劫持@Jorans回答，我会试试。

rs <- data.frame(C = unlist(dat[, grep("C",names(dat))]), 
       V = unlist(dat[, grep("V",names(dat))])) 

这将覆盖你的情况下，你的C和V不交替。