目的：为展示不同数据分布的差异。
1. ggplot2 实现
# 准备数据
dat=mtcars[, c("mpg", "cyl")]
colnames(dat)=c("value", "type")
head(dat)
# value type
#Mazda RX4 21.0 6
#Mazda RX4 Wag 21.0 6
#Datsun 710 22.8 4
cols=c("#F71480", "#76069A", "#FF8000")
#
p1=ggplot(dat, aes(x = value, fill = as.factor(type) ) ) +
geom_density(alpha = 0.8) +
scale_fill_manual(values = cols)+
facet_wrap(~type, ncol=1) + # 按气缸数分面
labs(title = "Density of MPG by Cylinder Count-A",
x = "Miles Per Gallon (MPG)",
y = "Density",
fill = "Cylinders") +
theme_classic(base_size = 14)+
theme(strip.background = element_blank(), # 去掉小标题背景
strip.placement = "outside");p1 # 小标题外部显示
#
p2=ggplot(dat, aes(x = value, fill = as.factor(type) ) ) +
geom_density(alpha = 0.8) +
scale_fill_manual(values = cols)+
facet_wrap(~type, ncol=1, scales="free_y") + # 按气缸数分面
labs(title = "Density of MPG by Cylinder Count-B",
x = "Miles Per Gallon (MPG)",
y = "Density",
fill = "Cylinders") +
theme_classic(base_size = 14)+
theme(strip.background = element_blank(), # 去掉小标题背景
strip.placement = "outside"); p2 # 小标题外部显示
#
2. 使用R包 ggridges
图放这里，方便和上图类似。
library(ggridges)
pB=ggplot(dat, aes(x = value, y = type, fill = factor(type, levels = c("4", "6", "8")) )) +
ggridges::geom_density_ridges(alpha = 0.7, show.legend = T) +
scale_fill_manual(values = cols)+
#scale_y_continuous( expand = c(0,0) )+
labs(title = "Density of MPG by Cylinder Count-C",
x = "Miles Per Gallon (MPG)",
y = "Density",
fill = "Cylinders") +
theme_classic(base_size = 14); pB
#
pB2=ggplot(dat, aes(x = value, y = type, fill = factor(type, levels = c("4", "6", "8")) )) +
ggridges::geom_density_ridges(alpha = 0.7, show.legend = T,
stat="binline", bins=25) +
scale_fill_manual(values = cols)+
#scale_y_continuous( expand = c(0,0) )+
labs(title = "Density of MPG by Cylinder Count-D",
x = "Miles Per Gallon (MPG)",
y = "Density",
fill = "Cylinders") +
theme_classic(base_size = 14); pB2
#
3. 去掉底部的空隙
pB3=ggplot(dat, aes(x = value, y = type, fill = factor(type, levels = c("4", "6", "8")) )) +
ggridges::geom_density_ridges(alpha = 0.7, show.legend = T,
scale = 2) +
scale_fill_manual(values = cols)+
#scale_y_continuous( expand = c(0,0) )+
labs(title = "Density of MPG by Cylinder Count-E\nset scale=2",
x = "Miles Per Gallon (MPG)",
y = "Density",
fill = "Cylinders") +
# 去掉底部
scale_y_discrete(expand = c(0, 0)) + # will generally have to set the `expand` option
scale_x_continuous(expand = c(0, 0)) + # for both axes to remove unneeded padding
coord_cartesian(clip = "on") + # to avoid clipping of the very top of the top ridgeline
theme_classic(base_size = 14); pB3
