14.2 Objects, working directory and workspace
- Possible storages
- “Workspace”: Storage within R
- Online on some server
- Q: Who has his own server?
- Working directory
getwd(): Display working directory
setwd(): Set working directory
dir(): Display files in working directory
- R does not understand
/in directory paths
#: Start comment that is not evaluated
- Meaningful names; No blanks
a <- 10or
a = 10: Assign something to an object
a: Type name to display content of object
rm(): Delete object from workspace
save(a, b, file = "myobjects.RData"): Save single objects
load("myobjects.RData"): Load saved objects
- …stores all objects generated during the session
- …is loaded automatically when you start R
ls(): Display workspace content
- R queries whether you would like to save the workspace when quitting it
14.2.1 Example: Objects, working directory and workspace
# Comments in the script start with # # Everything after # in the line is ignored by R # Send code with CTRL + R 5+5 getwd() # Display working directory # Generate a new folder on your hardrive called "2016_03_R_course_EUI" # Use this folder as your working directory, i.e. to store the downloaded files in there # If you need the path to your folder, copy it from the path field in the explorer (in windows) # The course files are available here: https://drive.google.com/folderview?id=0Bwer5wQoreiuMTRueFBGdDllNEk&usp=sharing # Set the your working directory to your new folder setwd(dir) dir() # Display content of working directory a <- 50 # Generate object that contains the number 50 a # Show content of object a = 70 a ls() # Display objects in workspace # Create a more complicated object thesenseoflife <- c("worshipping god","having fun","no idea") interesting <- thesenseoflife # define another object interesting # Q: How can I store the object "interesting" in the object "boring"? # Objectnames do not have blanks # Names should make sense and be systematic # e.g. for dummy variables: d.male.voter # e.g. variance of variables: var.income a <- 1 b <- 2 # Save objects a and b in the file "objects-a-and-b.RData" # in the working directory save(a,b,file="objects-a-and-b.RData") # Delete objects a and b rm(a,b) rm(list=ls()) ls() # display all objects load("objects-a-and-b.RData") # load objects from wd # Check if they were loaded a b
14.2.2 Exercise: Working directory, objects and workspace
- Open R and create a new script that you save under the name “yourlastname_rworkshop_2016.r”. In this script you save all the code that you use to solve the exercises from now on.
- Display the working directory.
- Change the working directory to your personal folder.
- Create two objects: The object “hundred” in which you save the number 100 and the object “xyz” in which you save the number 250.
- Check whether the created objects have really been stored in the workspace.
- Save the two objects in your working directory. Delete them from the workspace and load them again from your working directory.
- Check whether they are stored again in the working directory.