remove multiple sequenced files in R - r

i created multiple files named 1:100 + random letter to file:
for (i in 1:100){
file.create( paste0(i , ".txt"), showWarnings=TRUE)
# assign random LETTER to files
AZ <- sample(LETTERS,1)
cat(AZ,file = paste0(i,".txt"),append=TRUE)
#rename files, and create new file with append of LETTERS
name <- scan(file=paste0(i,".txt"), what="character")
file.rename(paste0(i,".txt"), paste0(i, name,".txt"))
Now, i have a lot of files named like "1T, 2C, 3Y,..., 100A" and i want to remove all these files (not removing the rest that has in the directory) with file.remove function, how should i remove them without naming one by one? and all the directory named "exercicio03" with everything inside?
ps.: i have already tried
file.remove(paste0(i,name,".txt"))
but is removing only the last file "100A"

You can easily remove only the files with names like "1T.txt, 2C.txt, 3Y.txt, ..., 100A.txt" with the following two lines of code:
remove.files <- list.files(".", pattern="^[0-9]{1,3}[A-Z]{1}\\.txt$")
do.call(file.remove,list(remove.files))
The script obtains all text files beginning with 1-3 digits followed by a letter in the current directory where you created them, and removes them.

Since you used a sample function, I think you can only be 100% sure that you remove only these files and no others, if you (did) save the values you became from that sample function.
So your first part should have been:
AZ<-NA
for (i in 1:100){
file.create( paste0(i , ".txt"), showWarnings=TRUE)
# assign random LETTER to files
AZ[i] <- sample(LETTERS,1)
cat(AZ[i],file = paste0(i,".txt"),append=TRUE)
#rename files, and create new file with append of LETTERS
name <- scan(file=paste0(i,".txt"), what="character")
file.rename(paste0(i,".txt"), paste0(i, name,".txt"))
}
That way you can afterwards remove them all via this :
for (i in 1:100){
file.remove(paste0(i,AZ[i],".txt"))
}

Related

How to call several variables in a for loop in R?

I have several .csv files of data stored in a directory, and I need to import all of them into R.
Each .csv has two columns when imported into R. However, the 1001st row needs to be stored as a separate variable for each of the .csv files (it corresponds to an expected value which was stored here during the simulation; I want it to be outside of the main data).
So far I have the following code to import my .csv files as matrices.
#Load all .csv in directory into list
dataFiles <- list.files(pattern="*.csv")
for(i in dataFiles) {
#read all of the csv files
name <- gsub("-",".",i)
name <- gsub(".csv","",name)
i <- paste(".\\",i,sep="")
assign(name,read.csv(i, header=T))
}
This produces several matrices with the naming convention "sim_data_L_mu" where L and mu are parameters from the simulation. How can I remove the 1001st row (which has a number in the first column, and the second column is null) from each matrix and store it as a variable named "sim_data_L_mu_EV"? The main problem I have is that I do not know how to call all of the newly created matrices in my for loop.
Couldn't post long code in comments so am writing here:
# Use dialog to select folder
# Full names are required to access files that are not in the current working directory
file_list <- list.files(path = choose.dir(), pattern = "*.csv", full.names = T)
big_list <- lapply(file_list, function(z){
df <- read.csv(z)
scalar <- df[1000,1]
return(list(df, scalar))
})
To access the scalar value from the third file, you can use
big_list[[3]][2]
The elements in big_list follow the order of file_list so you always know which file the data comes from.
If you use data.table::fread() instead of read.csv, you can play around with assigning column names, selecting which rows/columns to read etc. It's also considerably faster for large datafiles.
Hope this helps!

R Read files, manipulate file names and write files from/to folder

I have 10 files in a folder, which I have to manipulate. At the moment I do that manually meaning I adapt the script ten times. Now I'm trying to do that automatically.
First I get the file names by this command:
data <- list.files(path=".", pattern=".csv", full.names=TRUE)
Now I have the idea to iterate over the file names by a for-loop.
for(i in data) {
df <- read.csv("i", header=T)
df$sum <- sum(df$value1, df$value2)
write.table(df, file=i, row.names=FALSE)
}
I'm not sure if the read.csv command works. Moreover, t I don't want to rewrite the file. The originally file names have the following structure
30LOV_1.csv
30LOV_2.csv
100LOV_1.csv
2000LOV_1.csv
I want to add something like _20min to the file names, e.g.
30LOV_1_20min.csv
30LOV_2_20min.csv
100LOV_1_20min.csv
2000LOV_1_20min.csv
How can I achieve this? Do you have any suggestions?
Thanks
You can use sub to add additional information to the end of your filename. I used parenthesis to create a captured group to get the first part of the file name (.*) and then recalled it in the second part with \\1.
for(i in data) {
df <- read.csv("i", header=T)
df$sum <- sum(df$value1, df$value2)
filename <- sub("(.*).csv","\\1_20min.csv",i)
filename
# [1] "30LOV_1_20min.csv"
write.table(df, file=filename, row.names=FALSE)
}

Applying an R script to multiple files

I have an R script that reads a certain type of file (nexus files of phylogenetic trees), whose name ends in *.trees.txt. It then applies a number of functions from an R package called bGMYC, available here and creates 3 pdf files. I would like to know what I should do to make the script loop through the files for each of 14 species.
The input files are in a separate folder for each species, but I can put them all in one folder if that facilitates the task. Ideally, I would like to output the pdf files to a folder for each species, different from the one containing the input file.
Here's the script
# Call Tree file
trees <- read.nexus("L_boscai_1411_test2.trees.txt")
# To use with different species, substitute "L_boscai_1411_test2.trees.txt" by the path to each species tree
#Store the number of tips of the tree
ntips <- length(trees$tip.label[[1]])
#Apply bgmyc.single
results.single <- bgmyc.singlephy(trees[[1]], mcmc=150000, burnin=40000, thinning=100, t1=2, t2=ntips, start=c(1,1,ntips/2))
#Create the 1st pdf
pdf('results_single_boscai.pdf')
plot(results.single)
dev.off()
#Sample 50 trees
n <- sample(1:length(trees), 50)
trees.sample <- trees[n]
#Apply bgmyc.multiphylo
results.multi <- bgmyc.multiphylo(trees.sample, mcmc=150000, burnin=40000, thinning=100, t1=2, t2=ntips, start=c(1,1,ntips/2))
#Create 2nd pdf
pdf('results_boscai.pdf') # Substitute 'results_boscai.pdf' by "*speciesname.pdf"
plot(results.multi)
dev.off()
#Apply bgmyc.spec and spec.probmat
results.spec <- bgmyc.spec(results.multi)
results.probmat <- spec.probmat(results.multi)
#Create 3rd pdf
pdf('trees_boscai.pdf') # Substitute 'trees_boscai.pdf' by "trees_speciesname.pdf"
for (i in 1:50) plot(results.probmat, trees.sample[[i]])
dev.off()
I've read several posts with a similar question, but they almost always involve .csv files, refer to multiple files in a single folder, have a simpler script or do not need to output files to separate folders, so I couldn't find a solution to my specific problem.
Shsould I use a for loop or could I create a function out of this script and use lapply or another sort of apply? Could you provide me with sample code for your proposed solution or point me to a tutorial or another reference?
Thanks for your help.
It really depends on the way you want to run it.
If you are using linux / command line job submission, it might be best to look at
How can I read command line parameters from an R script?
If you are using GUI (Rstudio...) you might not be familiar with this, so I would solve the problem
as a function or a loop.
First, get all your file names.
files = list.files(path = "your/folder")
# Now you have list of your file name as files. Just call each name one at a time
# and use for loop or apply (anything of your choice)
And since you would need to name pdf files, you can use your file name or index (e.g loop counter) and append to the desired file name. (e.g. paste("single_boscai", "i"))
In your case,
files = list.files(path = "your/folder")
# Use pattern = "" if you want to do string matching, and extract
# only matching files from the source folder.
genPDF = function(input) {
# Read the file
trees <- read.nexus(input)
# Store the index (numeric)
index = which(files == input)
#Store the number of tips of the tree
ntips <- length(trees$tip.label[[1]])
#Apply bgmyc.single
results.single <- bgmyc.singlephy(trees[[1]], mcmc=150000, burnin=40000, thinning=100, t1=2, t2=ntips, start=c(1,1,ntips/2))
#Create the 1st pdf
outname = paste('results_single_boscai', index, '.pdf', sep = "")
pdf(outnam)
plot(results.single)
dev.off()
#Sample 50 trees
n <- sample(1:length(trees), 50)
trees.sample <- trees[n]
#Apply bgmyc.multiphylo
results.multi <- bgmyc.multiphylo(trees.sample, mcmc=150000, burnin=40000, thinning=100, t1=2, t2=ntips, start=c(1,1,ntips/2))
#Create 2nd pdf
outname = paste('results_boscai', index, '.pdf', sep = "")
pdf(outname) # Substitute 'results_boscai.pdf' by "*speciesname.pdf"
plot(results.multi)
dev.off()
#Apply bgmyc.spec and spec.probmat
results.spec <- bgmyc.spec(results.multi)
results.probmat <- spec.probmat(results.multi)
#Create 3rd pdf
outname = paste('trees_boscai', index, '.pdf', sep = "")
pdf(outname) # Substitute 'trees_boscai.pdf' by "trees_speciesname.pdf"
for (i in 1:50) plot(results.probmat, trees.sample[[i]])
dev.off()
}
for (i in 1:length(files)) {
genPDF(files[i])
}

Assigning Directory as a Variable in R

I need to create a function called PollutantMean with the following arguments: directory, pollutant, and id=1:332)
I have most of the code written but I can't figure out how to assign my directory as a variable. My current working directory is C:/Users/User/Documents. I tried writing the variable as:
directory <- "C:/Users/User/specdata" and that didn't work.
Next I tried the following:
directory <- list.files("specdata", full.names=TRUE) and that didn't work either.
Any ideas on how to change this?
If you are trying to assign the values in your current working directory to the variable "directory" Why not take the simple method and add:
directory <- getwd()
This should take the contents of the working directory and assign the values to the variable "directory".
I've already worker with directory as variables, I usually declare them like that
directory<-"C://Users//User//specdata//"
To take back your example.
Then, if I want to read a specific file in this directory, I will just go like :
read.table(paste(directory,"myfile.txt",sep=""),...)
It's the same process to write in a file
write.table(res,file=paste(directory,"myfile.txt",sep=""),...)
Is this helping ?
EDIT : you can then use read.csv and it will work fine
I think you are confused by the assignment operation in R. The following line
directory <- "C:/Users/User/specdata"
assigns a string to a new object that just happened to be called directory. It has the same effect on your working environment as
elephant <- "C:/Users/User/specdata"
To change where R reads its files, use the function setwd (short for set working directory):
setwd("C:/Users/User/specdata")
You can also specify full path names to functions that read in data (like read.table). For your specific problem,
# creates a list of all files ending with `csv` (i.e. all csv files)
all.specdata.files <- list.files(path = "C:/Users/User/specdata", pattern = "csv$")
# creates a list resulting from the application of `read.csv` to
# each of these files (which may be slow!!)
all.specdata.list <- lapply(all.specdata.files, read.csv)
Then we use dplyr::rbind_all to row-bind them into one file.
library(dplyr)
all.specdata <- rbind_all(all.specdata.list)
Then use colMeans to determine the grand means. Not sure how to do this without seeing the data.
Assuming that the columns in each of the 300+ csv files are the same, that is have column j contains the same type of data in all files, then the following example should be of use:
# let's use a temp directory for storing the files
tmpdr <- tempdir()
# Let's creat a large matrix of values and then split it into many different
# files
original_data <- data.frame(matrix(rnorm(10000L), nrow = 1000L))
# write each row to a file
for(i in seq(1, nrow(original_data), by = 1)) {
write.csv(original_data[i, ],
file = paste0(tmpdr, "/", formatC(i, format = "d", width = 4, flag = 0), ".csv"),
row.names = FALSE)
}
# get a character vector with the full path of each of the files
files <- list.files(path = tmpdr, pattern = "\\.csv$", full.names = TRUE)
# read each file into a list
read_data <- lapply(files, read.csv)
# bind the read_data into one data.frame,
read_data <- do.call(rbind, read_data)
# check that our two data.frames are the same.
all.equal(read_data, original_data)
# [1] TRUE

Building a mean across several csv files

I have an assignment on Coursera and I am stuck - I do not necessarily need or want a complete answer (as this would be cheating) but a hint in the right direction would be highly appreciated.
I have over 300 CSV files in a folder (named 001.csv, 002.csv and so on). Each contains a data frame with a header. I am writing a function that will take three arguments: the location of the files, the name of the column you want to calculate the mean (inside the data frames) and the files you want to use in the calculation (id).
I have tried to keep it as simple as possible:
pm <- function(directory, pollutant, id = 1:332) {
setwd("C:/Users/cw/Documents")
setwd(directory)
files <<- list.files()
First of all, set the wd and get a list of all files
x <- id[1]
x
get the starting point of the user-specified ID.
Problem
for (i in x:length(id)) {
df <- rep(NA, length(id))
df[i] <- lapply(files[i], read.csv, header=T)
result <- do.call(rbind, df)
return(df)
}
}
So this is where I am hitting a wall: I would need to take the user-specified input from above (e.g. 10:25) and put the content from files "010.csv" through "025.csv" into a dataframe to actually come up with the mean of one specific column.
So my idea was to run a for-loop along the length of id (e.g. 16 for 10:25) starting with the starting point of the specified id. Within this loop I would then need to take the appropriate values of files as the input for read.csv and put the content of the .csv files in a dataframe.
I can get single .csv files and put them into a dataframe, but not several.
Does anybody have a hint how I could procede?
Based on your example e.g. 16 files for 10:25, i.e. 010.csv, 011.csv, 012.csv, etc.
Under the assumption that your naming convention follows the order of the files in the directory, you could try:
csvFiles <- list.files(pattern="\\.csv")[10:15]#here [10:15] ... in production use your function parameter here
file_list <- vector('list', length=length(csvFiles))
df_list <- lapply(X=csvFiles, read.csv, header=TRUE)
names(df_list) <- csvFiles #OPTIONAL: if you want to rename (later rows) to the csv list
df <- do.call("rbind", df_list)
mean(df[ ,"columnName"])
These code snippets should be possible to pimp and incorprate into your routine.
You can aggregate your csv files into one big table like this :
for(i in 100:250)
{
infile<-paste("C:/Users/cw/Documents/",i,".csv",sep="")
newtable<-read.csv(infile)
newtable<-cbind(newtable,rep(i,dim(newtable)[1]) # if you want to be able to identify tables after they are aggregated
bigtable<-rbind(bigtable,newtable)
}
(you will have to replace 100:250 with the user-specified input).
Then, calculating what you want shouldn't be very hard.
That won't works for files 001 to 099, you'll have to distinguish those from the others because of the "0" but it's fixable with little treatment.
Why do you have lapply inside a for loop? Just do lapply(files[files %in% paste0(id, ".csv")], read.csv, header=T).
They should also teach you to never use <<-.

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