I'm glad to find this website.
I want to know how create many folders at once in R.
I know "dir.create" function, but I can't.
This is what I tried.
for (i in 1 : length(names)) {
name = names[i,1]
ifelse(dir.exists('users/',name), False, dir.create('users/',name))
}
dir_names <- c('a','b','c')
for (dir in dir_names){
if (!dir.exists(file.path('users',dir))) dir.create(file.path('users',dir))
}
Related
I have create a small script that passes a vector through a loop. In this loop I am using an if else statement to check if folder exists and if not to create the folder. However, I am getting error: Error in file.exists(i) : invalid 'file' argument. This has to due with file.exist(). I dont understand why this isnt ok. I check the man using help. Seems like this should be working.
folders<- c("RawData", "Output", "BCV", "DEplots", "DEtables", "PathwayOuts", "VolcanoPLots")
for(i in 1:length(folders)){
if (file.exists(i)){
cat(paste0(i, "already exists"))
} else {
cat(paste0(i, "does not exists"))
dir.create(i)
}
}
You are looping over an index (that is, 1:length(folders) is just the vector 1:7, not the values of the folders vector itself. The easiest solution is to loop over the vector itself:
for (i in folders) {
Or, if you still want to loop over the index:
for (i in 1:length(folders)) {
if (file.exists(folders[i])){
cat(paste0(folders[i], "already exists"))
}
else {
cat(paste0(folders[i], "does not exists"))
dir.create(folders[i])
}
}
A quick tip: if you are debugging a for-loop, the place to start is to add print(i) at the start of the loop. You would have immediately seen the problem: i was an integer, not the first value of the vector.
I am doing a "Noughts and Crosses" in R game for class and I have a problem.
I have to write the names of the two players in a file, which I have already created, but it gives me error because I must have mistaken something or have a order mistake regarding the functions "write.table", the data.frame I created for the names…
I upload the code:
write.table(names,"C://progra//players.txt", append=TRUE)
checknames(names)
names=data.frame(names=c(player1, player2), stringsAsFactors = FALSE)
print(names)
names=checknames(names)
}
checknames<-function(names)
{
print(names)
file.exists(players)
B=read.table("C://progra//players.txt")
player1=readline(prompt="Player 1, what's your name?: ")
for(i in 1:nrow(B))
{
if(player1==B[i,1])
Any suggestion Will be welcomed!
Thank you in advance!
I need to create 52 resources with capacity 2 in the Simmer simulation package. I am trying to do this by using a while loop that creates these resources for me, instead of creating each resource myself.
The idea is that I have a while loop as given below. In each loop, a resource should be created called Transport_vehicle1, Transport_vehicle2, ..., Transport_vehicle52, with capacity 2.
Now I do not know how to insert the number i in the name of the resource that I am trying to create
i<-1
while (i<=52)
{ env %>%
add_resource("Transport_vehicle"[i],capacity = 2)
i <- i+1
}
Could someone please help me out? Thanks!
You can use the paste method to concatenate the string and the number:
i<-1
while (i<=52)
{ env %>%
add_resource(paste("Transport_vehicle", i),capacity = 2)
i <- i+1
}
If you do not want a space between the string and the number add the sep="" argument
paste("Transport_vehicle", i, sep="")
or use
paste0("Transport_vehicle", i)
Been going around for hours with this. My 1st question online on R. Trying to creat a function that contains a loop. The function takes a vector that the user submits like in pollutantmean(4:6) and then it loads a bunch of csv files (in the directory mentioned) and binds them. What is strange (to me) is that if I assign the variable id and then run the loop without using a function, it works! When I put it inside a function so that the user can supply the id vector then it does nothing. Can someone help ? thank you!!!
pollutantmean<-function(id=1:332)
{
#read files
allfiles<-data.frame()
id<-str_pad(id,3,pad = "0")
direct<-"/Users/ped/Documents/LearningR/"
for (i in id) {
path<-paste(direct,"/",i,".csv",sep="")
file<-read.csv(path)
allfiles<-rbind(allfiles,file)
}
}
Your function is missing a return value. (#Roland)
pollutantmean<-function(id=1:332) {
#read files
allfiles<-data.frame()
id<-str_pad(id,3,pad = "0")
direct<-"/Users/ped/Documents/LearningR/"
for (i in id) {
path<-paste(direct,"/",i,".csv",sep="")
file<-read.csv(path)
allfiles<-rbind(allfiles,file)
}
return(allfiles)
}
Edit:
Your mistake was that you did not specify in your function what you want to get out from the function. In R, you create objects inside of function (you could imagine it as different environment) and then specify which object you want it to return.
With my comment about accepting my answer, I meant this: (...To mark an answer as accepted, click on the check mark beside the answer to toggle it from greyed out to filled in...).
Consider even an lapply and do.call which would not need return being last line of function:
pollutantmean <- function(id=1:332) {
id <- str_pad(id,3,pad = "0")
direct_files <- paste0("/Users/ped/Documents/LearningR/", id, ".csv")
# READ FILES INTO LIST AND ROW BIND
allfiles <- do.call(rbind, lapply(direct_files, read.csv))
}
ok, I got it. I was expecting the files that are built to be actually created and show up in the environment of R. But for some reason they don't. But R still does all the calculations. Thanks lot for the replies!!!!
pollutantmean<-function(directory,pollutant,id)
{
#read files
allfiles<-data.frame()
id2<-str_pad(id,3,pad = "0")
direct<-paste("/Users/pedroalbuquerque/Documents/Learning R/",directory,sep="")
for (i in id2) {
path<-paste(direct,"/",i,".csv",sep="")
file<-read.csv(path)
allfiles<-rbind(allfiles,file)
}
#averaging polutants
mean(allfiles[,pollutant],na.rm = TRUE)
}
pollutantmean("specdata","nitrate",23:35)
HI i just started learning R and finding this problem to be really interesting where I just run a code directly without wrapping in a function it works but when I place it inside a function it doesn't work, What can be possible reason?
fill_column<-function(colName){
count <- 0
for(i in fg_data$particulars) {
count <- count +1
if(grepl(colName, i) && fg_data$value[count] > 0.0){
fg_data[,colName][count] <- as.numeric(fg_data$value[count])
} else {
fg_data[,colName][count] <- 'NA'
}
}
}
fill_column('volume')
Where I am creating new column named volume it this string exists in particulars column.
I have added a comment where solution given by another question does not work for me, Please look at my comment below.
Finally I got it working but reading another answer on SO, here is the solution:
fill_column <- function(colName){
count <- 0
for(i in fg_data$particulars) {
count <- count +1
if(grepl(colName, i) && fg_data$value[count] > 0.0){
fg_data[,colName][count] <- as.numeric(fg_data$value[count])
} else {
fg_data[,colName][count] <- 'NA'
}
}
return(fg_data)
}
fg_data = fill_column('volume')
Now reason, Usually in any language when we modify global object inside any function it reflects on global object immediately but in R we have to return the modified object from function and then assign it again to global object to see our changes. or another way for doing this is to assign local object from within the function to global context using envir=.GlobalEnv.