Splitting a dataframe based in a column

Question

I would like to split my data.frame depending of a column tagged as "Chr". I would like to write these splitted objects in a .txt file automatically too.

My input:

Name   Chr  Position LTR
Prob1   1     55     0.2
Prob2   2     25     0.9
Prob3   3     25     0.7
Prob4   1     45     0.5

My First output:

Name   Chr  Position  LTR 
Prob1   1      55     0.2
Prob4   1      45     0.5

My second output:

 Name   Chr  Position  LTR 
 Prob2   2     25      0.9

My last output:

Name   Chr  Position  LTR 
Prob3   3     25      0.7

I am trying to do something like:

outfile <- paste0("newsplit",i,".txt") SPLIT PROCEDURES write.table(all, outfile, sep=";")

Where "i" is the correspondent chromosome (value in a "Chr" collumn).

Cheers!

Answer 1

First split your data.frame.

df.split <-split(df,df$Chr)# where df is your original dataframe 
           #and we split on Chr

Now, write it out to separate tab-separated files

lapply(names(df.split),function(x)
            write.table(file = paste0("df",x,".txt"),
            df.split[[x]], sep = "\t"))