Question

I have 102 text files, each containing of same type of data. Suppose data it is stored in variable d1 of the file f1.

In R:
I want to make plot between data in two files. say d1 vs d2 or d45 vs d85

I need to do these for all combinations ( 102C2 combinations)

How do I do that?

Answer 1

This is a bit of an out there request, as there is no way you would be able to make sense of that many plots. E.g.:

ncol(combn(1:102,2))

Gives a total of 5151 plots for the unique combinations between the 102 sets of data. If your professor wants to manually search through all those plots, he better pour himself a large coffee. I would seriously reconsider what you are trying to find out from this data and maybe redefine the scope of your investigation.

With that said, here’s some potential code that may or not be good advice given the circumstances. In fact, I’ll go so far as to suggest not running the below code with all of your files lest your computer explode.

# This is how you would read text files into a list,
# courtesy of this question (http://stackoverflow.com/q/9110110/496803):
# raw <- list.files(pattern="*.txt")
# listy <- lapply(raw, read.table)

# set up some mock data instead
listy <- list(1:3,4:6,7:9)

# get every possible combination
combos <- combn(1:length(listy),2)

# define a function to plot each combination of data  
multiplot <- function(x) {
    dev.new()
    plot(listy[[(x[1])]],listy[[x[2]]])
}

# Generate the plots separately.
# This will probably kill your R session with
# the number of plots you are generating.

apply(combos,2,multiplot)