I am batch converting a lot of .csv files to xlsx format using write.xlsx in the openxlsx package
I use the following to convert the list of files (there are over 200).
The reason I need to do this is for upload to a database, it will only accept xlsx files.
filenames <- list.files("C:/split files", pattern="*.csv", full.names=TRUE)
for(i in filenames) {
a <- read.csv(i)
new_name <- sub('.csv', '.xlsx', i, fixed = TRUE)
write.xlsx(a, new_name, row.names = F)
The problem I have is that the headers which used to have spaces in their names (again required format for the database) now have "." where the spaces used to be. Is there a simple way to add to the above code and replace the "." with " " ?
Try
read.csv(i, check.names = F)
You got that "." because R checks and converts your column names when reading the csv file. We can preserve original names by disabling that checking.
What is the proper way to append col names to the header of csv table which is generated by write.table command?
For example write.table(x, file, col.names= c("ABC","ERF")) throws error saying invalid col.names specification.Is there way to get around the error, while maintaining the function header of write.table.
Edit:
I am in the middle of writing large code, so exact data replication is not possible - however, this is what I have done:
write.table(paste("A","B"), file="AB.csv", col.names=c("A1","B1")) , I am still getting this error Error in write.table(paste("A","B"), file="AB.csv", col.names=c("A", : invalid 'col.names' specification.
Is that what you expect, tried my end
df <- data.frame(condition_1sec=1)
df1 <- data.frame(susp=0)
write.table(c(df,df1),file="table.csv",col.names = c("A","B"),sep = ",",row.names = F)
I am trying to read.table for a tab-delimited file using the following command:
df <- read.table("input.txt", header=FALSE, sep="\t", quote="", comment.char="",
encoding="utf-8")
There should be 30 million rows. However, after read.table() returns, df contains only ~6 million rows. And there is a warning message like this:
Warning message:
In read.table("input.txt", header = FALSE, sep = "\t", quote = "", :
incomplete final line found by readTableHeader on 'input.txt'
I believe read.table quits after encountering a special sympbol (ASCII code: 1A Substitute) in one of the string columns. In the input file, the only special character is tab because it is used to separate columns. Is there anyway to ask read.table to treat any other character as not special?
If you have 30 million rows. I would use fread rather than read.table. It is faster. Learn more about here http://www.inside-r.org/packages/cran/data.table/docs/fread
fread(input, sep="auto", encoding = "UTF-8" )
Regarding your issue with read.table. I think the solutions here should solve it.
'Incomplete final line' warning when trying to read a .csv file into R
I would like to read a large text file seperated by "|". So I used the below code.
sampleData <- read.table(file = '2013_4MM01_7-11_CD.txt',header =TRUE, sep = '|', nrows=10)
pos<- read.table.ffdf(file="2013_4MM01_7-11_CD.txt", header=TRUE, VERBOSE=TRUE,
FUN='read.table', sep = '|',
first.rows=10000, next.rows=50000, colClasses=classes)
I used "ff" package and checked my data after the running code ended. My data had some long numeric variable like "201304012371090245546" and the object read from the data was wrong. My ffdf object contained many duplicated rows and even a number that was not in the original txt file. I checked this by SAS. Please give me some useful advice.
This is a very simple issue and I'm surprised that there are no examples online.
I have a vector:
vector <- c(1,1,1,1,1)
I would like to write this as a csv as a simple row:
write.csv(vector, file ="myfile.csv", row.names=FALSE)
When I open up the file I've just written, the csv is written as a column of values.
It's as if R decided to put in newlines after each number 1.
Forgive me for being ignorant, but I always assumed that the point of having comma-separated-values was to express a sequence from left to right, of values, separated by commas. Sort of like I just did; in a sense mimicking the syntax of written word. Why does R cling so desperately to the column format when a csv so clearly should be a row?
All linguistic philosophy aside, I have tried to use the transpose function. I've dug through the documentation. Please help! Thanks.
write.csv is designed for matrices, and R treats a single vector as a matrix with a single column. Try making it into a matrix with one row and multiple columns and it should work as you expect.
write.csv(matrix(vector, nrow=1), file ="myfile.csv", row.names=FALSE)
Not sure what you tried with the transpose function, but that should work too.
write.csv(t(vector), file ="myfile.csv", row.names=FALSE)
Here's what I did:
cat("myVar <- c(",file="myVars.r.txt", append=TRUE);
cat( myVar, file="myVars.r.txt", append=TRUE, sep=", ");
cat(")\n", file="myVars.r.txt", append=TRUE);
this generates a text file that can immediately be re-loaded into R another day using:
source("myVars.r.txt")
Following up on what #Matt said, if you want a csv, try eol=",".
I tried with this:
write.csv(rbind(vector), file ="myfile.csv", row.names=FALSE)
Output is getting written column wise, but, with column names.
This one seems to be better:
write.table(rbind(vector), file = "myfile.csv", row.names =FALSE, col.names = FALSE,sep = ",")
Now, the output is being printed as:
1 1 1 1 1
in the .csv file, without column names.
write.table(vector, "myfile.csv", eol=" ", row.names=FALSE, col.names=FALSE)
You can simply change the eol to whatever you want. Here I've made it a space.
You can use cat to append rows to a file. The following code would write a vector as a line to the file:
myVector <- c("a","b","c")
cat(myVector, file="myfile.csv", append = TRUE, sep = ",", eol = "\n")
This would produce a file that is comma-separated, but with trailing commas on each line, hence it is not a CSV-file.
If you want a real CSV-file, use the solution given by #vamosrafa. The code is as follows:
write.table(rbind(myVector), file = "myfile.csv", row.names =FALSE, col.names = FALSE,sep = ",", append = TRUE)
The output will be like this:
"a","b","c"
If the function is called multiple times, it will add lines to the file.
One more:
write.table(as.list(vector), file ="myfile.csv", row.names=FALSE, col.names=FALSE, sep=",")
fwrite from data.table package is also another option:
library(data.table)
vector <- c(1,1,1,1,1)
fwrite(data.frame(t(vector)),file="myfile.csv",sep=",",row.names = FALSE)