###########
# R code for chapter 48 workspaces objects and history files.
# Book details:
# http://www.amazon.co.uk/Health-Science-Statistics-using-Commander/dp/190790431X
###########
# list all objects 
ls()  # list

# deleting (removing) all objects 
rm(list = ls(all=TRUE))

# To remove all objects in your workspace except the one called nasty_one type: 
rm(list=setdiff(ls(), "nasty_one"))

# search all the packages you have loaded 
search() 

# finding the structure of an objects
# str(object_name)

str(mydataframe)

# 48.1	Saving and loading  your workspace
# saving:
save.image("d:/mycurrentwork.rdata")
# or
save.image(file=file.choose())

# loading:
load("d:/mycurrentwork.rdata") 
# or 
load(file=file.choose())
# loading from a  website:
load(url("http://www.robin-beaumont.co.uk/virtualclassroom/book2data/cummingp245.rdata"))

# 48.2	Saving and loading your R commands - the history file
# loading:
loadhistory("d:/mycurrentwork.Rhistory") 
# saving:
savehistory(file = "filename.Rhistory")
# deleting default histroy file:
# This file is called .Rhistory, 
# The file is usually located in the default working directory which you 
# can find by typing  the command getwd() after you start R.
##########
# Once you have quit R use your usual file browser to navigate to 
# the correct directory, select the .Rhistory  file and then delete it