我有以下数据框：
expected observed group
1: 0.5371429 0.0000 1
2: 1.3428571 1.3736 1
3: 2.6857143 2.4554 1
4: 5.3714286 3.6403 1
5: 0.5294118 0.0000 2
6: 1.3235294 1.1494 2
7: 2.6470588 1.1364 2
8: 5.2941176 4.9774 2
9: 0.5201207 0.0000 3
10: 1.3003018 1.4327 3
11: 2.6006036 2.5918 3
12: 5.2012072 8.0769 3
13: 0.5155039 1.4851 4
14: 1.2887597 1.0638 4
15: 2.5775194 3.1700 4
16: 5.1550388 6.2500 4
17: 0.4976959 0.0000 5
18: 1.2442396 1.2384 5
19: 2.4884793 3.1073 5
20: 4.9769585 4.8148 5
我想根据组对每个数据集进行散点图，因此我有以下代码：
sp <- ggplot(new_df, aes(x = expected, y = observed, colour = group)) + geom_point()
sp + scale_color_gradientn(colours = rainbow(5))
and receive the below plot:
我的问题是如何向每个不同的组添加一条线性线（截距 = 0,0）？ 意思是，最后，我将有 5 条不同颜色的线性线，代表同一图上的每个组。
并且，有没有办法在图例中显示每条线的方程？
您可以使用以下命令获取线性线和方程/R2 文本geom_smooth from ggplot2 and stat_poly_eq from ggpmisc https://cran.r-project.org/web/packages/ggpmisc/vignettes/user-guide-1.html package
dat <- "expected observed group
0.5371429 0 1
1.3428571 1.3736 1
2.6857143 2.4554 1
5.3714286 3.6403 1
0.5294118 0 2
1.3235294 1.1494 2
2.6470588 1.1364 2
5.2941176 4.9774 2
0.5201207 0 3
1.3003018 1.4327 3
2.6006036 2.5918 3
5.2012072 8.0769 3
0.5155039 1.4851 4
1.2887597 1.0638 4
2.5775194 3.17 4
5.1550388 6.25 4
0.4976959 0 5
1.2442396 1.2384 5
2.4884793 3.1073 5
4.9769585 4.8148 5
"
library(ggplot2)
library(ggpmisc)
df <- read.table(text = dat, header = TRUE)
df$group <- factor(df$group)
formula <- y ~ x # needed for ggpmisc's equation and R2 text
# Put equation & R2 coef to the top left corner
ggplot(df, aes(expected, observed, colour = group)) +
geom_point(size = 2, alpha = 0.3) +
geom_smooth(method = "lm", formula = formula, se = FALSE) +
stat_poly_eq(aes(label = paste(..eq.label.., ..rr.label.., sep = "~~~~")),
label.x.npc = "left", label.y.npc = "top",
formula = formula, parse = TRUE, size = 4) +
scale_color_brewer(palette = "Dark2") +
theme_bw(base_size = 16)