myframe <-edit(data.frame())
myframe

ls()
rm(myframe)
ls()

##########################################################
# read.table()
# Reads a file in table format and creates a data frame 
# from it, with cases corresponding to lines and
# variables to fields in the file.
# File "first.dat"
#
#   var1,var2
#   this is , 11.4
#   a test., 12.3
first <- read.table("first.dat", header=TRUE, sep=",")
first
mean(first.var2) 
attach(first)
mean(var2)

###########################################################
# scan()
# Read data into a vector or list from the console or file
#
cat("TITLE extra line", "2 3 5 7", "11 13 17", file="ex.data", sep="\n")
pp <- scan("ex.data", skip = 1, quiet= TRUE)
scan("ex.data", skip = 1)
scan("ex.data", skip = 1, nlines=1)# only 1 line after the skipped one
scan("ex.data", what = list("","","")) # flush is F -> read "7"
scan("ex.data", what = list("","",""), flush = TRUE)
unlink("ex.data") # tidy up
############################################################
# sink()
# diverts R output to a connection
#
sink("sink-examp.txt")
i <- 1:10
outer(i, i, "*")
sink()
unlink("sink-examp.txt")
## Not run:
## capture all the output to a file.
zz <- file("all.Rout", open="wt")
sink(zz)
sink(zz, type="message")
try(log("a"))
## back to the console
sink(type="message")
sink()
try(log("a"))
## End(Not run)

###########################################################
# write.table() and read.table()
a <-c(5:8); b <- c(8:11); c<-c("This","is","a","test")
x <-data.frame(a,b,c)
write.table(x,file="foo.txt")
read.table("foo.txt")

###########################################################
# write.csv()  and read.csv()
#

write.csv(x,file="foo.csv",row.names=FALSE)
read.csv("foo.csv")

###########################################################
#
a <- rnorm(100)  # generate the data
x <- 1:100       # create the x-axis 
z <- lm(a~x)     # z becomes a linear model of "a" depending on "x"
z                # see that z is just an intercept and slope
plot(a)          # plot(a)
abline(z)        # plot the best-fit line above.
###########################################################
#
ts(1:10, frequency = 4, start = c(1959, 2)) # 2nd Quarter of 1959
print( ts(1:10, freq = 7, start = c(12, 2)), calendar = TRUE) # print.ts(.)
## Using July 1954 as start date:
gnp <- ts(cumsum(1 + round(rnorm(100), 2)),
start = c(1954, 7), frequency = 12)
plot(gnp) # using 'plot.ts' for time-series plot
## Multivariate
z <- ts(matrix(rnorm(300), 100, 3), start=c(1961, 1), frequency=12)
class(z)
plot(z)
plot(z, plot.type="single", lty=1:3)