[R] Using read.csv() to import data

David L Carlson dcarlson at tamu.edu
Mon Apr 25 17:02:19 CEST 2016

You can also use getwd() to see what folder/directory R is currently using and setwd("folder") to change it. Also list.files() lists all of the files in that current directory. 

The code you included assumes that the file is located in the root directory which is probably wrong. Try 

mammals <- read.csv("JPH_data.csv")

If you are just starting out learning R, you can create a directory to use with the book by  using the dir.create() function:


This will create a new folder in your default folder (probably called "My Documents"). Whenever you start R run setwd("LearnR") first so that anything you save goes in that folder. If you create .csv files, put them in that folder and R will find them easily. Also all of your R files will be in one place making them easier to find.

David L Carlson
Department of Anthropology
Texas A&M University
College Station, TX 77840-4352

-----Original Message-----
From: R-help [mailto:r-help-bounces at r-project.org] On Behalf Of Duncan Murdoch
Sent: Sunday, April 24, 2016 4:05 PM
To: Jason Hernandez; r-help at r-project.org
Subject: Re: [R] Using read.csv() to import data

On 24/04/2016 4:30 PM, Jason Hernandez via R-help wrote:
> I am just beginning to learn R, using _R for Dummies_ by Andrie de Vries and Joris Meys. I am using Windows 7, and RGui (64-bit) version 3.0.2. I have reached the chapter on "Getting Data Into and Out of R." But the code they use for importing data doesn't seem to be working for me.
> Their example is:> elements <- read.csv(file.path("f:", "elements.csv"))
> Since I don't have any such file, I am trying to use a file I have. I went to Excel, brought up my file titled JPH_data, and saved it as .csv (comma delineated) on my main hard drive C:
> Then I entered:>  mammals <- read.csv(file.path("C:", "JPH_data.csv"))
> I got the following:Error in file(file, "rt") : cannot open the connection
> In addition: Warning message:
> In file(file, "rt") :
>    cannot open file 'C:/JPH_data.csv': No such file or directory
> Aside from the obvious (how can it say "no such file or directory" when I just saved one such?), the "cannot open the connection" is also unexpected. What am I doing wrong here?
> Jason Hernandezno current affiliation

By far the easiest ways to enter Windows file paths are using the 
file.choose() and choose.files() functions.  Do something like

filename <- file.choose() # navigate to the file
mammals <- read.csv(filename)

and you should be fine.  The file.choose() function works on all 
platforms; choose.files() works only on Windows (and has more options, 
including allowing multiple files to be chosen).

Duncan Murdoch

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