How to merge columns from one file to another in R for many files?-CodePudding

I have over 100 files e.g. File_1,,,,,,File_100 like the below:

Position    Likelihood  Alpha
11885.0000  8.457955e-02    2.089548e 02
21877.3906  2.160398e 01    1.509296e-05
31869.7812  1.268591e 01    2.130559e-05

And more 100 files e.g. File_1,,,,,File_100 like the below:

Position    Likelihood  Alpha   StartPos    EndPos
11885.0000  0.000000e 00    1.200000e 03    11885.0000  32345.0000
21877.3906  0.000000e 00    1.200961e-03    11885.0000  32345.0000
31869.7812  1.083378e-01    6.004804e-04    11885.0000  32345.0000

I am trying to combine the StartPos and EndPos from the other files to the above files where I will have five columns eventually. So, I did something like this:

a<-read.table("File_1", header = T)
b<-read.table("File_1", header = T)
c<-cbind(a,b[4:5])
write.table(c, file="File_1.txt")

My question is, how can I put this command in a loop where it goes over all the 100 files from Directory A and 100 files from Directory B and produces a new file? The two groups of 100 files are in different directories. Thank you for your help.

CodePudding user response：

Try this but you must specify the folders in your system e.g. "/Users/mohamed/File_"

for(i in 1:100){
    a<-read.table(paste0("/Users/Documents/First_results/new_file/V-3/Report_Chr_" , i), header = T)
    b<-read.table(paste0("/Users/Documents/First_results/new_file/V-4/Report_Chr_" , i), header = T)
    c<-cbind(a,b[4:5])
    write.table(c, file=paste0("Report_Chr_" , i , ".txt"))
    
}

this must save the new files in your working directory.