Question 1: How can I retrieve (load) the work that is saved using history function in R?
Answer: The loadhistory() function will load an “.Rhistory“file.

> loadhistory(“d:/file_name.Rhistory”)

This function will load the file named “file_name.Rhistory” from D: drive.

The other way may be to access .Rhistory file through the file menu. For this click File and then Load history. From the dialog box appeared to browse the folder where you saved the .Rhistory file and click open to start working.

Question 2: How do I use a script of commands and functions saved in a text file?
Answer: The script of commands and functions saved in a text file (also called a script file) can be used by writing the following command.

> source(“d:/file_name.txt”)

The “file_name.txt” will load from D: drive.

Question 3: How do I get R to echo back the R commands and functions in a script file that I am sourcing into R? That is, the functions that I have written, I want to see these functions are being executed.
Answer: use echo=TRUE argument by using source() function

> source(“d:/file_name.txt”, echo=T)

Question 4: How do I close the help file when working on a Macintosh operating system?
Answer: Typing just q will close the help file and bring you back to the R console.

Question 5: How can I see a list of currently available objects in R?
Answer: Use the objects() or ls() functions to see the list of objects currently available

> objects()
> ls()

Question 6: How do I remove/delete unwanted objects and functions?
Answer: The rm() function can be used to delete or remove the objects that are not required. The commands  below will delete objects named object_name1 & object_name2 and functions named function_name1 & function_name2.

> rm(object_name1, object_names2)
> rm(function_name1, function_name2)