Error in loop reading multiple text files - r

I'm a bit stuck with this code... The purpose is to read only text files from a folder with few different kind of files, take a column for each one and create a data frame with every extracted column (cbind.fill is a hand-made function that add a new column and fill the "empty" spaces with NA values). Here is the code:
setwd("...folderOfInterest/")
genes_data <- data.frame()
for(i in list.files(pattern = "^GO_.*txt", full.names = TRUE)){
print(i) #this works perfectly, it only prints desired files...
q <- read.table(i, header = TRUE, sep = "\t", quote = NULL)
genes_data <- cbind.fill(genes_data, q[,2])
}
As #Adam B suggests, here is the print(i) output and a screenshot of the folder (folder_screenshot):
[1] "./GO_ALPHA_AMINO_ACID_CATABOLIC_PROCESS.xls"
[1] "./GO_ALPHA_AMINO_ACID_METABOLIC_PROCESS.xls"
[1] "./GO_ALPHA_BETA_T_CELL_ACTIVATION.xls"
[1] "./GO_AMINO_ACID_BETAINE_METABOLIC_PROCESS.xls"
[1] "./GO_AMINO_ACID_IMPORT.xls"
[1] "./GO_AMINO_ACID_TRANSMEMBRANE_TRANSPORT.xls"
[1] "./GO_AMINO_ACID_TRANSPORT.xls"
[1] "./GO_AMINOGLYCAN_BIOSYNTHETIC_PROCESS.xls"
[1] "./GO_ANGIOGENESIS.xls"
[1] "./GO_ANION_TRANSPORT.xls"
[1] "./GO_ANTIGEN_PROCESSING_AND_PRESENTATION.xls"
[1] "./GO_ANTIGEN_PROCESSING_AND_PRESENTATION_OF_ENDOGENOUS_ANTIGEN.xls"
Error in file(file, "rt") : cannot open the connection
In addition: Warning message:
In file(file, "rt") :
cannot open file './GO_ANTIGEN_PROCESSING_AND_PRESENTATION_OF_ENDOGENOUS_ANTIGEN.xls': No such file or directory
(note: the files' extension is .xls, but really they are .txt files)
It propmts this message:
Error in file(file, "rt") : cannot open the connection
In addition: Warning message:
In file(file, "rt") :
cannot open file './GO_ANTIGEN_PROCESSING_AND_PRESENTATION.txt': No such file or directory
Also running only q <- read.table(i, header = TRUE, sep = "\t", quote = NULL) appears this error message.
I think I'm in the correct folder (because print(i) works good), I've also changed full.names option and set list.files as a variable out the loop... but nothins seems to work. Please, if anybody has an idea it'll be welcome!

I've tried it on randomly generated files and it works. You probably do not need to cd into the directory with the data, just give the list.files a dir argument with the path to your data directory.
GOfls <- list.files("indata", pattern = "^GO_.*\\.txt", full.names = TRUE)
head(GOfls)
[1] "indata/GO_amswylfbgp.txt" "indata/GO_amswylfbgptxt" "indata/GO_apqqqktvir.txt"
[4] "indata/GO_arwudmbzsr.txt" "indata/GO_autljyljgn.txt" "indata/GO_beeqcmnayk.txt"
# lapply -> do.call for reading and binding the data is better approach
gene_data <- do.call('cbind', lapply(GOfls, function(path) read.delim(path)[,2]))
# have a look at the data
dim(gene_data)
[1] 100 100
I have tried to reproduce your problem this way (it's optional text):
dir.create("indata")
fls <- lapply(1:100, function(i) data.frame(matrix(rnorm(1000), ncol = 10)))
names(fls) <- replicate(100, paste0("./indata/", "GO_",
paste0(sample(letters, 10, replace = T),
collapse = ""), ".txt"
)
)
lapply(names(fls), function(x) write.table(fls[[x]], x, quote = F, sep = "\t"))
head(dir("indata"))
[1] "GO_acebruujkw.pdf" "GO_amswylfbgp.txt" "GO_amswylfbgptxt" "GO_apqqqktvir.txt"
[5] "GO_arwudmbzsr.txt" "GO_autljyljgn.txt"
# I have added some renamed .txt files (.pdf, .tiff, .gel) to the indata
rm(list = ls())

That's solved! It's a bit strange but copying the folder of interest into the desktop the code seems to work again.
A mate and I saw that hard disk's activity was collapsed, so we thought that maybe there could be a problem in the process of reading... so copying the folder was the (simple) solution!
Nevertheless, if anybody has an idea that explains this strange situation I'm sure it'll be useful! Thanks a lot!
EDIT
I've done some tests and maybe the problem is the name of the folder path, which it'd too long and crashes the loop.

I think it's because you're searching for .xls files, but then trying to open it at as a .txt file
In excel try saving the files as comma or tab delimited text files.
If you want to open excel files directly they have a few packages that can do that. Try readxl.

Related

Error in file(file, "rt") : cannot open the connection - Unsure of what to do

I am currently working through Coursera's R Programming course and have hit a bit of a snag with this assignment. I have been getting various errors (not I'm not totally sure I've nailed down) but this is a new one and no matter what I do I can't seem to shake it.
Whenever I run the below code it comes back with
Error in file(file, "rt") : cannot open the connection
pollutantmean <- function (directory, pollutant, id){
files<- list.files(path = directory, "/", full.names = TRUE)
dat <- data.frame()
dat <- sapply(file = directory,"/", read.csv)
mean(dat["pollutant"], na.rm = TRUE)
}
I have tried numerous different solutions posted here on SO for this issue but none of it has worked. I made sure that I am running after setting the working directory to the folder with all of the CSV files and I can see all of the files in the file pane. I have also moved that working directory around a few times since some of the suggestions were to put it on the desktop, etc. but none of that has worked. I am currently running R Studio as an admin but that does not seem to have done anything and I have also modified the permissions on the specdata file to ensure there's no weird restrictions there. Any help is appreciated.
Here are two possible implementations:
# list all files in "directory", read them, combine and then take mean of "pollutant" column
pollutantmean_1 <- function (directory){
files <- list.files(path = directory, full.names = TRUE)
dat <- lapply(file = directory, read.csv)
dat <- data.table::rbindlist(dat) |> as.data.frame()
mean(dat[, 'pollutant' ], na.rm = TRUE)
}
# list all files in "directory", read them, take the mean of "pollutant" column for each file and return them
pollutantmean_2 <- function (directory){
files <- list.files(path = directory, full.names = TRUE)
dat <- lapply(file = directory, read.csv)
pollutant_means <- sapply(dat, function(x) mean(x[ , 'pollutant' ], na.rm = TRUE))
names(pollutant_means) <- basename(files)
pollutant_means
}

Extract column from multiple csv files and merge into new data frame in R

I want to extract column called X1 out of 168 different .csv files, called table3_2, table3_3, table3_4, table3_5..., table3_168, all held in one folder (folder1). Then, merge into one new df. Contents of the column is factor.
Trying this code but can't get it to work.
folder1 <- "folder1"
folder2 <- "folder2" # destination folder
write_to <- function(file.name) {
file.name <- paste0(tools::file_path_sans_ext(basename(file.name)), ".csv")
df <- read.csv(paste(folder1, file.name, sep = "/"), header = FALSE, sep = "/")[X1]
write.csv(df, file = past(folder2, file.name, sep= "/"))
}
files <- list.files(path = folder1, pattern = "*.csv")
lapply(X = paste(folder1, files, sep= "/"), write_to)
This comes up with the error:
Error in file(file, "rt") : cannot open the connection
In addition: warning message:
In file(file, "rt") :
cannot often file folder1/folder1.csv: No such file or directory
So, I am not calling in the correct names of the table, and maybe not directing R to the correct folder (I've set the wd to folder1).
Any suggestions would be greatly appreciated.
Many thanks
There are a few minor issues that stand out, e.g. you have a typo in file = past(folder2, file.name, sep= "/") (should be paste() not past()) but perhaps a simpler approach would suit, e.g. using vroom:
library(vroom)
files <- fs::dir_ls(glob = "table3_*csv")
data <- vroom(files, id = "ID", col_select = c(ID, X1))
data
vroom_write(data, file = "~/xx/folder2/new_df.csv")
# replace "xx" with your path
Does this approach solve your problem?

Convert .txt files into .CSV files in a directory using a loop

Fresh lettuce here so don't laugh at my questions:
Say I have a folder containing 40 individual .txt files and I would like to convert them into .csv format.
To have an end product : a new folder with 40 individual .csv files.
I have seen similar question posted and their code, however the code did run but the .csv files is nothing like the orginal .txt file: all the data are scrambled.
Since I want to keep the header, and I want to read all the data/rows in the .txt file. I made some cosmetic changes to the code, still didnt run and returned a warning "Error in file(file, "rt") : cannot open the connection
In addition: Warning message:
In file(file, "rt") :
cannot open file 'C:/Users/mli/Desktop/All TNFa controls in the training patients ctrl_S1018263__3S_TNFaCHx_333nM+0-1ugml_none.txt': Invalid argument"
My code as below:
directory <- "C:/Users/mli/Desktop/All TNFa controls in the training patients"
ndirectory <- "C:/Users/mli/Desktop/All TNFa controls in the training patients/CSV"
file_name <- list.files(directory, pattern = ".txt")
files.to.read <- paste(directory, file_name, sep="\t")
files.to.write <- paste(ndirectory, paste0(sub(".txt","", file_name),".csv"), sep=",")
for (i in 1:length(files.to.read)) {
temp <- (read.csv(files.to.read[i], sep="\t", header = T))
write.csv(temp, file = files.to.write[i])
}
When you paste your path with the name of your file at line 4 and 5, use /, to obtain a new path in a character string. The sep value is what the function will put when it will paste together multiple strings.
> paste('hello','world',sep=" ")
[1] "hello world"
> paste('hello','world',sep="_")
[1] "hello_world"
This is different of the sep value you need in read.csv that define the character between each column of you csv file.

How can I use a variable as an argument to a function, specifically unz() in R

I am writing an R function that reads CSV files from a subdirectory in a ZIP file without first unzipping it, using read.csv() and unz().
The CSV files are named with leading 0 as in 00012.csv, 00013.csv etc.
The function has the following parameters: MyZipFile, ASubDir, VNum (a vector e.g. 1:42) which forms the filename.
What I want is to use the variable PathNfilename in unz().
# Incorporate the directory in the ZIP file while constructing the filename using stringr package
PathNfilename <- paste0("/", ASubDir, "/", str_pad(Vnum, 5, pad = "0"), ".csv", sep="")
What works is:
csvdata <- read.csv(unz(description = "MyZipFile.zip", filename = "ASubDirectory/00039.csv"), header=T, quote = "")
What I need is something along these lines of this:
csvdata <- read.csv(unz(description = "MyZipFile.zip", filename = PathNFileName), header=T, quote = "")
The error that I get is:
Error in open.connection(file, "rt") : cannot open the connection
In addition: Warning message:
In open.connection(file, "rt") :
cannot locate file '/ASubDir/00039.csv' in zip file 'MyZipFile.zip'
I'd like to understand why I'm getting the error and how to resolve it. Is it a scoping issue?
Try with some PathFilename without the leading /
ASubDir <- "ASubDirectory"
Vnum <- 1:5
PathNfilename <- file.path(ASubDir,
paste0(str_pad(Vnum, 5, pad = "0"), ".csv")
)
PathNfilename
#> [1] "ASubDirectory/00001.csv" "ASubDirectory/00002.csv"
#> [3] "ASubDirectory/00003.csv" "ASubDirectory/00004.csv"
#> [5] "ASubDirectory/00005.csv"

Converting twitteR results to data frame

I have a simple for loop to write the past 100 tweets of a few usernames to .csv files:
library(twitteR)
mclist <- read.table('usernames.txt')
for (mc in mclist)
{
tweets <- userTimeline(mc, n = 100)
df <- do.call("rbind", lapply(tweets, as.data.frame))
write.csv(df, file=paste("Desktop/", mc, ".csv", sep = ""), row.names = F)
}
I mostly followed what I've read on StackOverflow but I continue to get this error message:
Error in file(file, ifelse(append, "a", "w")) :
invalid 'description' argument
In addition: Warning message:
In if (file == "") file <- stdout() else if (is.character(file)) { :
the condition has length > 1 and only the first element will be used
Where did I go wrong?
I just cleaned up the code a bit, and everything started working.
Step 1: Let's set the working directory and load the 'twitteR' package.
library(twitteR)
setwd("C:/Users/Dinre/Desktop") # Replace with your desired directory
Step 2: First, we need to load a list of user names from a flat text file. I'm assuming that each line in the text file has one username, like so:
[contents of usernames.txt]
edclef
notch
dkanaga
Let's load it using the 'scan' function to read each line into an array:
mclist <- scan("usernames.txt", what="", sep="\n")
Step 3: We'll loop through the usernames, just like you did before, but we're not going to refer to the directory, since we're going to use the same directory for output as input. The original code had a syntax error in attempting to referring to the desktop directory, and we're just going to sidestep that.
for (mc in mclist){
tweets <- userTimeline(mc, n = 100)
df <- do.call("rbind", lapply(tweets, as.data.frame))
write.csv(df, file=paste(mc, ".csv", sep = ""), row.names = F)
}
I end up with three files on the desktop, and all the data seems to be correct.
edclef.csv
notch.csv
dkanaga.csv
Update: If you really want to refer to different directories within your code, use the '.' character to refer to the parent directory. For instance, if your working directory is your Windows user profile, you would refer to the 'Desktop' folder like so:
setwd("C:/Users/Dinre")
...
write.csv(df, file=paste("./Desktop/". mc, ".csv", sep = ""), row.names = F)
There's a convenience function in the package twListToDF which will handle the conversion of the list of tweets to a data.frame.
Since your mclist is a data.frame, you can replace your for by apply
apply( mclist, 1,function(mc){
tweets <- userTimeline(mc, n = 100)
df <- do.call("rbind", lapply(tweets, as.data.frame))
write.csv(df, file=paste("Desktop/", mc, ".csv", sep = ""), ##!! Change Desktop to
## something like Desktop/tweets/
row.names = F)
})
PS :
The userTimeline function will only work if the user requested has a
public timeline, or you have previously registered a OAuth object
using registerTwitterOAuth

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