需求描述

上次內容講述了在做好的圖層中添加特定的陰影區(qū)界逛，來顯示著重突出的部分。本次內容學習一下在圖層中添加特定斜率的直線并在圖例中顯示械念，我們知道添加特定斜率的直線一般分為水平線geom_hline朦拖，垂直線geom_vline和特定斜率的直線geom_abline，添加對應的圖例諸如scale_shape_manual峰档，scale_linetype_manual,scale_color_manual,...

1. 數(shù)據(jù)導入

本次內容以數(shù)據(jù)集mtcars為例，來演示圖形繪制。

rm(list = ls(all=TRUE))#清除所有變量內存
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. 圖形繪制(散點圖)

#設置斜率直線屬性
df_abline <- data.frame(intercept=c(.2,1.05,2),slope=c(3, 1.5,.7),linetype=factor(c(1,3,5)))
#作圖
p <- ggplot(data=mtcars, aes(x=wt, y=drat)) + 
  geom_point(aes(shape = factor(cyl),color = factor(cyl))) +#賦值給顏色或性狀屬性(分組因子變量)
  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 添加水平或者垂直線

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. 散點圖+趨勢線

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

4. 條形圖

(a) 將vline添加到現(xiàn)有繪圖并使其出現(xiàn)在ggplot2圖例中？
(b) 將一條線添加到ggplot2圖并調整圖例
(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

后記

全是圖吼砂，和移栽的代碼是為總結記錄

PS

2020/05/05 22:40
于疫情勞動節(jié)假期