期中作業

Statistic <- c(68,85,74,88,63,78,90,80,58,63)
Math <- c(85,91,74,100,82,84,78,100,51,70)

plot(Statistic,Math,
     pch=20,
     col="skyblue",
     xlab="統計成績",
     ylab="數學成績",
     main="班級的統計與數學成績")

hist(Statistic,
     col= "grey",
     main ="班上的統計與數學成績",
     xlab ="統計成績",
     ylab ="次數")

hist(Math,
     col= "grey",
     main ="班上的統計與數學成績",
     xlab ="數學成績",
     ylab ="次數")

# Load ggplot2
library(ggplot2)

# Create data
data <- data.frame(
  社團類型=c("休閒娛樂","知識閱讀","體育競技","科學創新","公益活動") ,  
  次數=c(185,32,36,28,25)
  )

# Barplot
ggplot(data, aes(x=社團類型, y=次數)) + 
  geom_bar(stat = "identity", width=0.2) 

data2<- c(185,32,36,28,25)
labels<- c("休閒娛樂","知識閱讀","體育競技","科學創新","公益活動")

pie(data2,labels,main ="社團的比例", col=heat.colors(length(data2)))

# plot 
ggplot(data, aes(x=社團類型, y=次數)) + 
  geom_segment( aes(x=社團類型, xend=社團類型, y=0, yend=次數)) + 
  geom_point( size=5, color="blue", fill=alpha("skyblue", 0.3), alpha=0.7, shape=21, stroke=2)

japanese<-c(84,63,61,49,89,51,59,53,79,91)
stem(japanese)

## 
##   The decimal point is 1 digit(s) to the right of the |
## 
##   4 | 9
##   5 | 139
##   6 | 13
##   7 | 9
##   8 | 49
##   9 | 1

mean(japanese)

## [1] 67.9

median(japanese)

## [1] 62

as.numeric(names(table(japanese)))[which.max(table(japanese))]

## [1] 49

sd(japanese)

## [1] 16.25115

var(japanese)

## [1] 264.1

Q1 <- quantile(japanese, 1 / 4) 
Q2 <- quantile(japanese, 2 / 4) 
Q3 <- quantile(japanese, 3 / 4) 
Q1

##  25% 
## 54.5

Q3

##   75% 
## 82.75