I got a question about reading a file into data frame using R.
I don't understand "getwd" and "setwd", do we must do these before reading the files?
and also i need to print some of the columns in the data frame, and only need to print 1 to 30,how to do this?
Kinds regards
getwd tells you what your current working directory is. setwd is used to change your working directory to a specified path. See the relevant documentation here or by typing ? getwd or ? setwd in your R console.
Using these allows you to shorten what you type into, e.g., read.csv by just specifying a filename without specifying its full path, like:
setwd('C:/Users/Me/Documents')
read.csv('myfile.csv')
instead of:
read.csv('C:/Users/Me/Documents/myfile.csv')
Related
I define a DataFrame named data and want to write it into .csv file. I used writetable("result_data.csv", data) but it doesn't work.
This is the dataframe
error details
To write a data frame to a disk you should use the CSV.jl package like this (also make sure that you have write right to the directory you want to save the file on Juliabox):
using CSV
CSV.write("result_data.csv", data)
If this fails then please report back in the comment I will investigate it further.
I'm trying to write out an R output to a text file that is not saved as .txt but as some other unique identifier (for example .prt). I know that's possible with matlab, but I don't know how to get that to work with R.
I can't find any package to do that, and when I try to specify the extension in the file name it give me an error and doesn't save.
Any idea would be greatly welcome! Thank you.
Unless you are using some specialized package, a lot of standard R functions for writing data to files have a file= parameter (or similar) to let you specify whatever the filename (and extension) you want. For example:
dummy.data <- matrix(rnorm(25),ncol=5)
### in reality you could just write file="dummyfile.prt" as one string
### but for demonstration purposes, you can use paste0() or paste(,sep='')
### to create a new file name using some variable prefix and your extension
### ".prt"
### sep='\t' makes the output tab-delimited
write.table(dummy.data,file=paste0("dummyfile",".prt"),sep='\t')
Situation
I wrote an R program which I split up into multiple R-files for the sake of keeping a good code structure.
There is a Main.R file which references all the other R-files with the 'source()' command, like this:
source(paste(getwd(), dirname1, 'otherfile1.R', sep="/"))
source(paste(getwd(), dirname3, 'otherfile2.R', sep="/"))
...
As you can see, the working directory needs to be set correctly in advance, otherwise, this could go wrong.
Now, if I want to share this R program with someone else, I have to pass all the R files and folders in relative order of each other for things to work. Hence my next question.
Question
Is there a way to replace all the 'source' commands with the actual R script code which it refers to? That way, I have a SINGLE R script file, which I can simply pass along without having to worry about setting the working directory.
I'm not looking for a solution which is an 'R package' (which by the way is one single directory, so I would lose my own directory structure). I simply wondering if there is an easy way to combine these self-referencing R files into one single file.
Thanks,
Ok I think you could use something like scaning all the files and then writting them again in the same new one. This can be done using readLines and sink:
sink("mynewRfile.R")
for(i in Nfiles){
current_file = readLines(filedir[i])
cat("\n\n#### Current file:",filedir[i],"\n\n")
cat(current_file, sep ="\n")
}
sink()
Here I have supposed all your file directories are in a vector filedir with length Nfiles, I guess you can adapt that
I want to export a dataset in the MASS package to SPSS for further investigation. I'm looking for the EuStockMarkets data set in the package.
As described in http://www.statmethods.net/input/exportingdata.html, I did:
library(foreign)
write.foreign(EuStockMarkets, "c:/mydata.txt", "c:/mydata.sps", package="SPSS")
I got a text file but the sps file is not a valid SPSS file. I'm really looking for a way to export the dataset to something that a SPSS can open.
As Thomas has mentioned in the comments, write.foreign doesn't generate native SPSS datafiles (.sav). What it does generate is the data in a comma delimited format (the .txt file) and a basic syntax file for reading that data into SPSS (the .sps file). The EuStockMarkets data object class is multivariate time series (mts) so when it's exported the metadata is lost and the resulting .sps file, lacking variable names, throws an error when you try to run it in SPSS. To get around this you can export it as a data frame instead:
write.foreign(as.data.frame(EuStockMarkets), "c:/mydata.txt", "c:/mydata.sps", package="SPSS")
Now you just need to open mydata.sps as a syntax file (NOT as a datafile) in SPSS and run it to read in the datafile.
Rather than exporting it, use the STATS GET R extension command. It will take a specified data frame from an R workspace/dataset and convert it into a Statistics dataset. You need the R Essentials for Statistics and the extension command, which are available via the SPSS Community site (www.ibm.com/developerworks/spssdevcentral)
I'm not trying to answer a question that has been answered. I just think there is something else to complement for other users looking for this.
On your SPSS window, you just need to find the first line of code and edit it. It should be something like this:
"file-name.txt"
You need to find the folder path where you're keeping your file:
"C:\Users\DELL\Google Drive\Folder-With-Your-File"
Then you just need to add this path to your file's name:
"C:\Users\DELL\Google Drive\Folder-With-Your-File\file-name.txt"
Otherwise SPSS will not recognize the .txt file.
Sorry if I'm repeating some information here, I just wanted to make it easier to understand.
I suppose that EuStockMarkets is a (labelled) data frame.
This should work and even keep the variable and value labels:
require(sjlabelled)
write_spss(EuStockMarkets, "mydata.sav")
Or you try rio:
rio::export(EuStockMarkets, "mydata.sav")
I am EXTREMELY new to R, and programming in general, so thank you for your patience.
I am trying to write a script which reads values from a .txt file and after some manipulation plots the results. I have two questions which are somewhat coupled.
First, is there a function which asks the user to identify the location of a file? i.e. User runs script. Script opens up file navigation prompt and requests user to navigate to and select relevant file.
Currently, I have to manually identify the file and location in R. e.g.
spectra.raw <- read.table("C:\Users\...\file1.txt", row.names=NULL, header = TRUE)
I'd rather have the user identify the file location each time the script is run. This will be used by non-tech people, and I don't trust them to copy/paste file locations into R.
The second question I've been struggling with is, is it possible to create a variable name based off the file selected? For example, if the user selects "file1.txt" I'd like R to assign the output of read.table() to a variable named "file1.raw" much like the above "spectra.raw"
If it helps, all the file names will have the exact same number of characters, so if it's possible to select the last say 5 characters from the file location, that would work.
Thank you very much, and please excuse my ignorance.
See file.choose. Though I believe it behaves slightly differently on different platforms, so beware of that.
See assign, i.e. assign("fileName",value). You'll want to parse the file path that file.choose spits back using string manipulation functions like substr or strsplit.
Try
file.choose
I think it can do what you want.
For example,
myfile <- file.choose()
Enter file name: adataset.Rdata
load(myfile)
myfile contains the name of the file so you don't have to do anything special.