pacman::p_load(Ecdat, HSAUR3, tidyr, datasets, dplyr, foreign, mosaic, memisc, gmodels, GGally)
EX02
dta_02 <- Caschool %>%
group_by(county) %>%
sample_n(1)
with(dta_02, plot(mathscr ~ readscr,
xlab = "average math score",
ylab = "average reading score"))

EX04
head(dta_04 <- backpain)
## ID status driver suburban
## 1 1 case yes yes
## 2 1 control yes no
## 3 2 case yes yes
## 4 2 control yes yes
## 5 3 case yes no
## 6 3 control yes yes
dta_04 <- backpain %>%
group_by(status, driver, suburban) %>%
summarise(n = n()) %>%
ungroup() %>%
spread(status, n) %>%
mutate(total = case + control); dta_04
## # A tibble: 4 x 5
## driver suburban case control total
## <fct> <fct> <int> <int> <int>
## 1 no no 26 47 73
## 2 no yes 6 7 13
## 3 yes no 64 63 127
## 4 yes yes 121 100 221
EX05
library(datasets)
dta_05 <- merge(state.x77, USArrests, "row.names")
cor(dta_05[, -1])
## Population Income Illiteracy Life Exp Murder.x
## Population 1.00000000 0.20822756 0.10762237 -0.06805195 0.34364275
## Income 0.20822756 1.00000000 -0.43707519 0.34025534 -0.23007761
## Illiteracy 0.10762237 -0.43707519 1.00000000 -0.58847793 0.70297520
## Life Exp -0.06805195 0.34025534 -0.58847793 1.00000000 -0.78084575
## Murder.x 0.34364275 -0.23007761 0.70297520 -0.78084575 1.00000000
## HS Grad -0.09848975 0.61993232 -0.65718861 0.58221620 -0.48797102
## Frost -0.33215245 0.22628218 -0.67194697 0.26206801 -0.53888344
## Area 0.02254384 0.36331544 0.07726113 -0.10733194 0.22839021
## Murder.y 0.32024487 -0.21520501 0.70677564 -0.77849850 0.93369089
## Assault 0.31702281 0.04093255 0.51101299 -0.62665800 0.73976479
## UrbanPop 0.51260491 0.48053302 -0.06219936 0.27146824 0.01638255
## Rape 0.30523361 0.35738678 0.15459686 -0.26956828 0.57996132
## HS Grad Frost Area Murder.y Assault
## Population -0.09848975 -0.3321525 0.02254384 0.32024487 0.31702281
## Income 0.61993232 0.2262822 0.36331544 -0.21520501 0.04093255
## Illiteracy -0.65718861 -0.6719470 0.07726113 0.70677564 0.51101299
## Life Exp 0.58221620 0.2620680 -0.10733194 -0.77849850 -0.62665800
## Murder.x -0.48797102 -0.5388834 0.22839021 0.93369089 0.73976479
## HS Grad 1.00000000 0.3667797 0.33354187 -0.52159126 -0.23030510
## Frost 0.36677970 1.0000000 0.05922910 -0.54139702 -0.46823989
## Area 0.33354187 0.0592291 1.00000000 0.14808597 0.23120879
## Murder.y -0.52159126 -0.5413970 0.14808597 1.00000000 0.80187331
## Assault -0.23030510 -0.4682399 0.23120879 0.80187331 1.00000000
## UrbanPop 0.35868123 -0.2461862 -0.06154747 0.06957262 0.25887170
## Rape 0.27072504 -0.2792054 0.52495510 0.56357883 0.66524123
## UrbanPop Rape
## Population 0.51260491 0.3052336
## Income 0.48053302 0.3573868
## Illiteracy -0.06219936 0.1545969
## Life Exp 0.27146824 -0.2695683
## Murder.x 0.01638255 0.5799613
## HS Grad 0.35868123 0.2707250
## Frost -0.24618618 -0.2792054
## Area -0.06154747 0.5249551
## Murder.y 0.06957262 0.5635788
## Assault 0.25887170 0.6652412
## UrbanPop 1.00000000 0.4113412
## Rape 0.41134124 1.0000000
ggpairs(dta_05[, -1])
