ggplot2: Grammar
Dữ liệu
head ( mpg )
## [1] 18 15 18 16 17 15
Xây dựng biểu đồ điểm
qplot ( displ , hwy , data = mpg , colour = factor ( cyl ))
## Error: ggplot2 doesn't know how to deal with data of class numeric
qplot ( displ , hwy , data = mpg , colour = factor ( cyl ), geom = "line" )
## Error: ggplot2 doesn't know how to deal with data of class numeric
qplot ( displ , hwy , data = mpg , colour = factor ( cyl ), geom = "bar" , stat = "identity" , position = "identity" )
## Error: ggplot2 doesn't know how to deal with data of class numeric
# A complex plot without name qplot ( displ , hwy , data = mpg , colour = factor ( cyl )) + geom_smooth ( data = subset ( mpg , cyl != 5 ), method = "lm" )
## Error: ggplot2 doesn't know how to deal with data of class numeric
Một biểu đồ phức tạp hơn
# A more complex plot with facets and multiple layers. qplot ( displ , hwy , data = mpg , facets = . ~ year ) + geom_smooth ()
## Error: ggplot2 doesn't know how to deal with data of class numeric
Các thành phần của ngữ pháp phân lớp
x <- 1 : 10 y <- factor ( letters [ 1 : 5 ]) qplot ( x , x , size = x )
qplot ( x , x , 1 : 10 , colour = x )
qplot ( y , y , 1 : 10 , shape = y )
qplot ( y , y , 1 : 10 , colour = y )
x 1 <- c ( 1 , 10 ) y 1 <- c ( 1 , 5 ) p <- qplot ( x 1 , y 1 , geom = "blank" , xlab = NULL , ylab = NULL ) + theme_bw () p
p + coord_trans ( y = "log10" )
p + coord_polar ()
p <- qplot ( displ , hwy , data = mpg , colour = factor ( cyl ))
## Error: ggplot2 doesn't know how to deal with data of class numeric
summary ( p )
## data: [0x0] ## mapping: x = x1, y = y1 ## faceting: facet_null() ## ----------------------------------- ## geom_blank: ## stat_identity: ## position_identity: (width = NULL, height = NULL)
# Save plot object to disk # save(p, file = "plot.rdata") # Load from disk # load("plot.rdata") # Save png to disk # ggsave("plot.png", width = 5, height = 5)