R ggplot2 geom_point 积分

geom_point(
  mapping = NULL,
  data = NULL,
  stat = "identity",
  position = "identity",
  ...,
  na.rm = FALSE,
  show.legend = NA,
  inherit.aes = TRUE
)

p <- ggplot(mtcars, aes(wt, mpg))
p + geom_point()


# Add aesthetic mappings
p + geom_point(aes(colour = factor(cyl)))

p + geom_point(aes(shape = factor(cyl)))

# A "bubblechart":
p + geom_point(aes(size = qsec))


# Set aesthetics to fixed value
ggplot(mtcars, aes(wt, mpg)) + geom_point(colour = "red", size = 3)


# \donttest{
# Varying alpha is useful for large datasets
d <- ggplot(diamonds, aes(carat, price))
d + geom_point(alpha = 1/10)

d + geom_point(alpha = 1/20)

d + geom_point(alpha = 1/100)

# }

# For shapes that have a border (like 21), you can colour the inside and
# outside separately. Use the stroke aesthetic to modify the width of the
# border
ggplot(mtcars, aes(wt, mpg)) +
  geom_point(shape = 21, colour = "black", fill = "white", size = 5, stroke = 5)


# \donttest{
# You can create interesting shapes by layering multiple points of
# different sizes
p <- ggplot(mtcars, aes(mpg, wt, shape = factor(cyl)))
p +
  geom_point(aes(colour = factor(cyl)), size = 4) +
  geom_point(colour = "grey90", size = 1.5)

p +
  geom_point(colour = "black", size = 4.5) +
  geom_point(colour = "pink", size = 4) +
  geom_point(aes(shape = factor(cyl)))


# geom_point warns when missing values have been dropped from the data set
# and not plotted, you can turn this off by setting na.rm = TRUE
set.seed(1)
mtcars2 <- transform(mtcars, mpg = ifelse(runif(32) < 0.2, NA, mpg))
ggplot(mtcars2, aes(wt, mpg)) +
  geom_point()
#> Warning: Removed 4 rows containing missing values (`geom_point()`).

ggplot(mtcars2, aes(wt, mpg)) +
  geom_point(na.rm = TRUE)

# }