Hello！I'm using a package from github. I've installed it. But when i follow the guideline. I met a error about opening file.

    require(rmotifx)
    rmotifx
    
    fg.path = system.file("extdata", "fg-data-ck2.txt", package="motifx")
    
    bg.path = system.file("extdata", "bg-data-serine.txt", package="motifx")
    
    fg.seqs = readLines(fg.path)
    
    Warning message:
    In file(con, "r") :
      file("") only supports open = "w+" and open = "w+b": using the former
    
    bg.seqs = readLines(bg.path)
    
    Warning message:
    In file(con, "r") :
      file("") only supports open = "w+" and open = "w+b": using the former
    
    head(fg.seqs)
    
    character(0)
    
    head(bg.seqs)
    
    character(0)

Those two file are peptide sequence file. So i need to readLines them. I'm wondering how can i fix it?
Thank you!

here's the original tutorial: https://github.com/omarwagih/rmotifx
I believe this is an issue with how you are calling your data, rather than something with the `readLines()` function. After trying the example on my console I got the same error. The  `system.files()` calls don't work so the objects `bg.path` and `fg.path` are empty, and when `readLines()` tries to search for the .txt files it can't find them. So, you just have to tell R exactly where to find the files you want it to run. You can do this by just including the entire file path in the `readLines()` call:

    fg.seqs = readLines(file("C:/Users/Gregory/Documents/R/win-library/3.3/rmotifx/extdata/fg-data-ck2.txt"))
    bg.seqs = readLines(file("C:/Users/Gregory/Documents/R/win-library/3.3/rmotifx/extdata/bg-data-serine.txt")) 
    head(fg.seqs)
    ###[1] "KRAGGEESQFEMDI_" "SSYGISETTLEEIFL" "SYGISETTLEEIFLK"
    ###[4] "FLKVAEESGVDAETS" "WSLNKEDTSEQVVPV" "KKLSVPTSDEEDEVP"


*EDIT: You'll need to find the files on your computer and change the path.