ggplot2:basic complete example

Data：diamonds

library(ggplot2)

qplot(x, y = NULL, ..., data, facets = NULL, margins = FALSE,
  geom = "auto", xlim = c(NA, NA), ylim = c(NA, NA), log = "",
  main = NULL, xlab = deparse(substitute(x)),
  ylab = deparse(substitute(y)), asp = NA, stat = NULL, position = NULL)


qplot( carat, price, data = diamonds）

qplot(carat, price, data = dsmall, geom = c("point", "smooth"), 
  span = 0.2) ##曲线的波动

qplot( carat, price, data = diamonds, 
  geom = c("point", "smooth")，alpha = I(1/10))

qplot( carat, price, data = diamonds, geom ="point",colour= I(alpha("red", 0.2))) ##注意I()的用法

geom="jitter"
geom="boxplot"
geom="histogram"
geom="density"
geom="smooth"
geom="point"
geom="bar"
geom="line"
geom="path"
geom="blank"
geom="area"
geom="tile"
geom="path"

　　变换

qplot(log(carat), log(price), data = diamonds)

qplot(carat, price, data = diamonds, log = "xy")

qplot(
   carat, price/carat, data = diamonds, 
   ylab = expression(frac(price,carat)), ##expression的用法
   xlab = "Weight (carats)",  
   main="Small diamonds", 
   xlim = c(.2,1)##这里可以.2
)

qplot(carat, ..density.., data = diamonds, facets = color ~ .,
  geom = "histogram", binwidth = 0.1, xlim = c(0, 3))

qplot(carat, data = diamonds, geom = "density", colour = color)
qplot(carat, data = diamonds, geom = "histogram", fill = color)

qplot(color, data = diamonds, geom = "bar", weight = carat) +
  scale_y_continuous("carat") 

qplot(carat, price, data=diamonds, colour= I("red")) + ggtitle("legend_box")+theme(plot.title = element_text(hjust = 0.5))#调主题位置

ggsave("plot.png", width = 5, height = 5)