[R] How I can rearrange columns in data.frame?

[arun]

Hi,
Try this:
dat2<-dat[order(as.numeric(gsub("preV(\\d+).*","\\1",colnames(dat))))]
 dat2
#  preV15A1b preV59A1b preV1001A1b preV2032A1b preV2035A1b
#1      0.57      0.05        0.59        0.40        0.95
#2      0.62      0.57        0.30        0.80        0.67
#3      0.51      0.03        0.78        0.24        0.81
#4      0.95      0.50        0.43        0.34        0.80


identical(dat1,dat2)
#[1] TRUE
A.K.


Hi R-User, 
I am wondering how I can rearrange columns in a table in R. I do 
have very big data set (4500 columns). I have given an example of the 
data set. 

> dput(dat) 
structure(list(preV1001A1b = c(0.59, 0.3, 0.78, 0.43), preV15A1b = c(0.57, 
0.62, 0.51, 0.95), preV2032A1b = c(0.4, 0.8, 0.24, 0.34), preV2035A1b = c(0.95, 
0.67, 0.81, 0.8), preV59A1b = c(0.05, 0.57, 0.03, 0.5)), .Names = c("preV1001A1b", 
"preV15A1b", "preV2032A1b", "preV2035A1b", "preV59A1b"), class = "data.frame", row.names = c(NA, 
-4L)) 

I wanted to make like this 
> dput(dat1) 
structure(list(preV15A1b = c(0.57, 0.62, 0.51, 0.95), preV59A1b = c(0.05, 
0.57, 0.03, 0.5), preV1001A1b = c(0.59, 0.3, 0.78, 0.43), preV2032A1b = c(0.4, 
0.8, 0.24, 0.34), preV2035A1b = c(0.95, 0.67, 0.81, 0.8)), .Names = c("preV15A1b", 
"preV59A1b", "preV1001A1b", "preV2032A1b", "preV2035A1b"), class = "data.frame", row.names = c(NA, 
-4L)) 
Any suggestions. 
KG