3.3.1

• 1
  color = "blue"をaes()の中に入れない

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

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

• 2
  manufacture, model, trans, drv, fl, class,

mpg

## # A tibble: 234 x 11
##    manufacturer model displ  year   cyl trans drv     cty   hwy fl    class
##    <chr>        <chr> <dbl> <int> <int> <chr> <chr> <int> <int> <chr> <chr>
##  1 audi         a4      1.8  1999     4 auto… f        18    29 p     comp…
##  2 audi         a4      1.8  1999     4 manu… f        21    29 p     comp…
##  3 audi         a4      2    2008     4 manu… f        20    31 p     comp…
##  4 audi         a4      2    2008     4 auto… f        21    30 p     comp…
##  5 audi         a4      2.8  1999     6 auto… f        16    26 p     comp…
##  6 audi         a4      2.8  1999     6 manu… f        18    26 p     comp…
##  7 audi         a4      3.1  2008     6 auto… f        18    27 p     comp…
##  8 audi         a4 q…   1.8  1999     4 manu… 4        18    26 p     comp…
##  9 audi         a4 q…   1.8  1999     4 auto… 4        16    25 p     comp…
## 10 audi         a4 q…   2    2008     4 manu… 4        20    28 p     comp…
## # … with 224 more rows

• 3
  連続値はshapeで指定できない　　

# continuous
ggplot(data = mpg) +
      geom_point(mapping = aes(x = displ, y = hwy, color = cty, size = cty))

# character
ggplot(data = mpg) +
      geom_point(mapping = aes(x = displ, y = hwy, color = trans, size = trans, shape = trans))

## Warning: Using size for a discrete variable is not advised.

## Warning: The shape palette can deal with a maximum of 6 discrete values
## because more than 6 becomes difficult to discriminate; you have
## 10. Consider specifying shapes manually if you must have them.

## Warning: Removed 96 rows containing missing values (geom_point).

• 4
  直線になる

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

• 5
  プロットの枠線サイズを指定している

# strokeアリ
ggplot(data = mtcars, mapping = aes(x = wt, y = mpg)) +
      geom_point(shape = 21, colour = "black", fill = "white", size = 5, stroke = 5)

# strokeナシ
ggplot(data = mtcars, mapping = aes(x = wt, y = mpg)) +
      geom_point(shape = 21, colour = "black", fill = "white", size = 5)

• 6

ggplot(data = mpg, mapping = aes(x = hwy, y = cty)) +
      geom_point(mapping = aes(color = displ < 5))