# Rproject10_flow_occ_regressions.r
# 1.0 Read in data ----
#       See Problem 10.9.50,
#       data from:  http://pems.eecs.berkeley.edu
# For each of three lanes, the
#   flow (number of cars)
#   occupancy (percentage of time a car was over the loop)
#
#     1740  5-minute intervals
#     Lane 1 farthest left lane, lane 2 center, lane 3 farthest right

sep=",",stringsAsFactors = FALSE,

Timestamp2 = strptime(flowocc$Timestamp, "%m/%d/%Y %H:%M:%S") #plot(Timestamp2, flowocc$Lane.1.Occ)
#plot(flowocc$Lane.1.Occ) flowocc$Timestamp=Timestamp2

lmfit1=lm(Lane.3.Occ ~ Lane.1.Occ, data=flowocc)
plot(flowocc$Lane.1.Occ, flowocc$Lane.3.Occ)

lmfit1=lm(Lane.3.Occ ~ Lane.1.Occ, data=flowocc)
abline(lmfit1,col="green")

plot(flowocc$Lane.1.Occ, lmfit1$residuals)
abline(h=0,col="gray")

qqnorm(lmfit1$residuals) # Consider two subsets ind.subset1=(flowocc$Lane.1.Occ < .18)

ind.subset2=(flowocc$Lane.1.Occ > .18) # For first subset: plot(flowocc$Lane.1.Occ[ind.subset1], flowocc$Lane.3.Occ[ind.subset1]) lmfit1.subset1=lm(Lane.3.Occ ~ Lane.1.Occ, data=flowocc, weight=1*ind.subset1) abline(lmfit1.subset1,col="green") plot(flowocc$Lane.1.Occ[ind.subset1], lmfit1.subset1$residuals[ind.subset1]) abline(h=0,col="gray") qqnorm(lmfit1.subset1$residuals[ind.subset1])

# For second subuset:

plot(flowocc$Lane.1.Occ[ind.subset2], flowocc$Lane.3.Occ[ind.subset2])

lmfit1.subset2=lm(Lane.3.Occ ~ Lane.1.Occ, data=flowocc, weight=1*ind.subset2)
abline(lmfit1.subset2,col="green")

plot(flowocc$Lane.1.Occ[ind.subset2], lmfit1.subset2$residuals[ind.subset2])

abline(h=0,col="gray")

qqnorm(lmfit1.subset2\$residuals[ind.subset2])

# For second subuset: