需求描述
上次内容讲述了在做好的图层中添加特定的阴影区，来显示着重突出的部分。本次内容学习一下在图层中添加特定斜率的直线并在图例中显示，我们知道添加特定斜率的直线一般分为水平线geom_hline，垂直线geom_vline和特定斜率的直线geom_abline，添加对应的图例诸如scale_shape_manual，scale_linetype_manual,scale_color_manual,...
1. 数据导入
本次内容以数据集mtcars为例，来演示图形绘制。
rm(list = ls(all=TRUE))#清除所有变量内存
library(ggplot2)#load packages
data(mtcars)
head(mtcars)
> head(mtcars)
mpg cyl disp hp drat wt qsec vs am gear carb
Mazda RX4 21.0 6 160 110 3.90 2.620 16.46 0 1 4 4
Mazda RX4 Wag 21.0 6 160 110 3.90 2.875 17.02 0 1 4 4
Datsun 710 22.8 4 108 93 3.85 2.320 18.61 1 1 4 1
Hornet 4 Drive 21.4 6 258 110 3.08 3.215 19.44 1 0 3 1
Hornet Sportabout 18.7 8 360 175 3.15 3.440 17.02 0 0 3 2
Valiant 18.1 6 225 105 2.76 3.460 20.22 1 0 3 1
2. 图形绘制(散点图)
#设置斜率直线属性
df_abline <- data.frame(intercept=c(.2,1.05,2),slope=c(3, 1.5,.7),linetype=factor(c(1,3,5)))
#作图
p <- ggplot(data=mtcars, aes(x=wt, y=drat)) +
geom_point(aes(shape = factor(cyl),color = factor(cyl))) +#赋值给颜色或性状属性(分组因子变量)
geom_abline(data=df_abline, aes(intercept=intercept,slope=slope, linetype=linetype)) +
labs(color="",linetype="") +
scale_shape_manual(name = "",
values=c(1,2,4),
labels=c("4","6","8")) +
scale_linetype_manual(name = "",
values=c(1,3,2),
labels=c("a","b","c"))
p
geom_abline
2.1 添加水平或者垂直线
df_hline <- data.frame(yintercept=c(3,3.5,4),linetype=factor(c(1,3,5)))
#df_vline <- data.frame(xintercept=c(2,3.5,5),linetype=factor(c(1,3,5)))
p1 <- ggplot(data=mtcars, aes(x=wt, y=drat)) +
geom_point(aes(shape = factor(cyl),color = factor(cyl))) +
geom_hline(data = df_hline, aes(yintercept = intercept, linetype = linetype)) +
labs(color="",linetype="") +
scale_shape_manual(name = "",
values=c(1,2,4),
labels=c("4","6","8")) +
scale_linetype_manual(name = "",
values=c(1,3,2),
labels=c("a","b","c"))
p1
Rplot_hline
Rplot_vline
3. 散点图+趋势线
df_abline <- data.frame(intercept=c(.2,1.05,2),slope=c(3, 1.5,.7),linetype=factor(c(1,3,5)))
p2 <- ggplot(data=mtcars, aes(x=wt, y=drat)) +
geom_point(aes(shape = factor(cyl),color = factor(cyl))) +
stat_smooth(aes(linetype="regression"),method = "lm",
formula = y ~ x, se = TRUE, colour = 1, size = 0.5) +
geom_abline(data = df_abline, aes(intercept = intercept,slope = slope, linetype = linetype)) +
labs(color="",linetype="") +
scale_shape_manual(name = "",
values=c(1,2,4),
labels=c("4","6","8")) +
scale_linetype_manual(name = "",
values=c(1,3,2,4),
labels=c("a","b","c","regression"))
p2
Rplot_gression
可以看出当加入趋势线后，legend发生了一些变化
4. 条形图
(a) 将vline添加到现有绘图并使其出现在ggplot2图例中？
(b) 将一条线添加到ggplot2图并调整图例
(c) How to make geom_abline show_guide line types show up in legend correctly
set.seed(20200505)
df <- data.frame(val=rnorm(300, 75, 10))
cuts1 <- data.frame(Thresholds="Thresholds A", vals=c(43, 70, 90))
cuts2 <- data.frame(Thresholds="Thresholds B", vals=c(46, 79, 86))
cuts <- rbind(cuts1,cuts2)
p3 <- ggplot(data=df, aes(x=val)) +
geom_histogram() +
geom_vline(data=cuts,
aes(xintercept=vals,
linetype=Thresholds,
colour = Thresholds),
show.legend = TRUE)
p3
Rplot_barplot
Rplot02_hline
Rplot02_xyz
后记
全是图，和移栽的代码是为总结记录
PS
2020/05/05 22:40
于疫情劳动节假期
