Q1
##Q1
Sys.setlocale("LC_TIME", "English")
## [1] "English_United States.1252"
dta1 <- weekdays(seq(as.Date("1993-12-24"), by = "1 years", length = 100))
dta1 <- as.factor(dta1)%>%as.data.frame()
colnames(dta1) <- c("weekday")
##
ggplot(data = dta1,aes(x = weekday))+
geom_bar(width = 0.5)+
labs(x = "")+
theme_bw()

Q2
as.Date("2017-06-30")-as.Date("2012-09-01")
## Time difference of 1763 days
Q3
dta3 <- read.csv("http://titan.ccunix.ccu.edu.tw/~psycfs/dataM/Data/calls_nyc.csv")
str(dta3)
## 'data.frame': 24 obs. of 2 variables:
## $ Hour : num 0.5 1.5 2.5 3.5 4.5 5.5 6.5 7.5 8.5 9.5 ...
## $ Calls: int 1080 910 770 780 380 390 200 300 275 395 ...
##
ggplot(dta3, aes(Hour, Calls, group = 1)) +
geom_bar(width = 1, stat = "identity", fill = "cyan",
color = "gray", alpha = 0.2) +
geom_abline(intercept = mean(dta3$Calls), slope = 0,
size = 1, color = "lightpink") +
coord_polar(theta = "x", start = -pi/12) +
theme_bw()

Q4
dta4 <- readLines("http://titan.ccunix.ccu.edu.tw/~psycfs/dataM/Data/nobel_winners.txt")
dta4 <- dta4[2:19]
dta4 <- unlist(strsplit(dta4, "\""))
dta4 <- unique(dta4[dta4!=""])
dta4 <- unique(dta4[dta4!=" "])
dta4 <- unique(dta4[dta4!=" "])
dta4 <- dta4%>%data.frame(ID = dta4[seq(1,54,by = 3)], Born = dta4[seq(2,54,by = 3)], Died = dta4[seq(3,54,by = 3)])
dta4 <- dta4[1:18,2:4]
dta4$Born <- as.Date(dta4$Born,"%B %d, %Y")
dta4$Died <- as.Date(dta4$Died,"%B %d, %Y")
dta4$Born[8] <- as.Date("1892-06-26")
#mean life expectancy
dta4 <- dta4%>%mutate(life = (Died-Born)/365)
Q5
dta5 <- read.table("http://titan.ccunix.ccu.edu.tw/~psycfs/dataM/Data/tw_to_us.txt",header = F)
str(dta5)
## 'data.frame': 23 obs. of 1 variable:
## $ V1: int 3637 2553 4564 6780 12029 12250 17560 22590 30960 33530 ...
dta5$year <- c(seq(1950,1990,by = 5),seq(1991,2004,by = 1))
ggplot(data = dta5,aes(x = year,y = V1))+
geom_point()+
geom_line()+
labs(title = "ROC(Taiwan) Students in the U.S.A (1950-2004)")+
theme_bw()

Q6
dta6 <- read.csv("http://titan.ccunix.ccu.edu.tw/~psycfs/dataM/Data/Visit_TW.csv")
dta6 <- dta6%>%mutate(Arrival = as.Date(Arrival,"%Y/%m/%d"),
Depature = as.Date(Depature,"%Y/%m/%d"))
dta6 <- dta6%>%mutate(stay = Depature-Arrival)
dta6$stay <- as.numeric(dta6$stay)
dta6$stay[dta6$stay == 0] <- 1
dta6$perday <- dta6$Expense/dta6$stay
mean(dta6$perday)
## [1] 6861.279
boxplot(dta6$perday,horizontal = T)

Q7
dta7 <- read.table("http://titan.ccunix.ccu.edu.tw/~psycfs/dataM/Data/chiayi_rainfall.txt",header = T,na.strings = ".")
dta7 <- dta7%>%gather(key = month,value = rainfall,2:13)
dta7$month <- as.factor(dta7$month)
ggplot(data = dta7,aes(x = month,y = rainfall))+
geom_boxplot()+
labs(x = "",y = "Rainfall(mm)",title = "Average monthly rainfall at Chia-Yi county from 1969 to 2010")+
theme_bw()

Q8
dta8 <- as.data.frame(cpi)
str(dta8)
## 'data.frame': 103 obs. of 1 variable:
## $ cpi: num 9.9 10 10.1 10.9 12.8 15.1 17.3 20 17.9 16.8 ...
dta8$year <- seq(1913,2015,by = 1)
dta8$cpiChange <- c(NA,diff(dta8$cpi))
##
plot(cpiChange~year,data = dta8,type = "b",xlab = "Year",ylab = "Annual Change in CPI")
abline(h = mean(dta8$cpiChange,na.rm = T),col = "red",lty = 2)
grid()
