hw05

library(ggplot2)
library(tidyverse)

## ── Attaching packages ───────────────────────────────── tidyverse 1.3.0 ──

## ✓ tibble  2.1.3     ✓ dplyr   0.8.3
## ✓ tidyr   1.0.0     ✓ stringr 1.4.0
## ✓ readr   1.3.1     ✓ forcats 0.4.0
## ✓ purrr   0.3.3

## ── Conflicts ──────────────────────────────────── tidyverse_conflicts() ──
## x dplyr::filter() masks stats::filter()
## x dplyr::lag()    masks stats::lag()

data(mpg)

#Q1:(displ)與(hwy)的關係，以及用顏色區分車種(class)

ggplot(data = mpg) +
  geom_point(mapping = aes(x = displ, y = hwy, color = class))

#Q2:再加上線性趨勢

ggplot(data = mpg, aes(x = displ, y =hwy)) +
geom_point(mapping = aes(x = displ, y = hwy, color = class))+
stat_smooth(method = 'lm')

## `geom_smooth()` using formula 'y ~ x'

#Q3:畫出下列圖形(提示：geom_smooth(aes(x = displ, y = hwy, linetype = drv)))

ggplot(data = mpg) +
geom_point(data = mpg, mapping = aes(x = displ, y = hwy, color = drv)) +
geom_smooth(mapping = aes(x = displ, y = hwy, linetype = drv),
show.legend = FALSE)            

## `geom_smooth()` using method = 'loess' and formula 'y ~ x'