# The second file is in comma delimited format, so the "read.table" function (or variation) can be used
# ?read.table
# read.csv will convert the data
trk06 <- read.csv("H06trk.csv")

dim(trk06)

trk06[1:10,]

#  All of the modifications for this file have been put in the file "trk.modify"
#  We can use the "source" function to read and execute the commands
source("trk.modify.R")

# summary of tracker data
summary(trk06)

# drop HHID and PN
names(trk06)

trk06 <- trk06[,-c(6,7)]

summary(trk06)

#  Merge subset of "B" data with the tracker data
# ?merge
objects()

model.data <- merge(H96B50.54,trk06)

dim(model.data)

names(model.data)

# It looks like the merge went well now try some models
# since we are done with cleaning and transforming data, we can use the "attach" function
attach(model.data)

# Use search() to see where data is located
search()

# model.data is now in the search path at #2
objects(2)

# All of the variables are now objects at level 2.  The "masked" message is because
# we have a HHIDPN in our .GlobalEnv and also model.data.  Remove the copy in .GlobalEnv
remove(HHIDPN)

# Since the data we are using is attached, there is no need to specify the frame name
table(DEGREE,GENDER)

table(GENDER,RACE)

# Try a model
lm(DPW ~ Age + Cigs)

# To display additional information, use the summary function
summary(lm(DPW ~ Age + Cigs))

# To write the output to a file, use the "sink" function
sink(file="model1.output")

summary(lm(DPW ~ Age + Cigs))

# To return to displaying output on the console, use "sink" with no options
sink()