使用回归方程在ggplot2中的多个facet_grid中具有良好的geom_text质量

时间:2016-11-29 16:00:02

标签: r plot ggplot2

我想使用ggplot2在不同的方面绘制几个回归方程......我认为我成功归功于this post

但是geom_text字体很难看,因为它在同一个文本区域中多次复制相同的字母:

iris <- iris
iris2 <- data.frame(iris, family = c(rep(rep(1:2,25),3)))
iris3 <- data.frame(iris2, group = paste(iris2$Species, iris2$family, sep = "_"))

intercept <- ddply(iris3, .(group), function(x)  coefficients(lm(Petal.Length~Petal.Width,x)))
rcarre <- ddply(iris3, .(group), function(x) summary(lm(Petal.Length~Petal.Width,x))$r.squared) 

names(rcarre) <- c("group", "R2") 
names(intercept) <- c("group", "intercept", "slope") 
coefs <- merge(intercept, rcarre) 
coefs <- data.frame(coefs,
                eq = paste("Y=",round(coefs$intercept,2),"+",round(coefs$slope, 2),"x",", ","R2=",round(coefs$R2,2), sep = ""))
coefs$eq = as.character(coefs$eq)

iris4 <- merge(iris3, coefs)

ggplot(iris4, aes(x = Petal.Width, y = Petal.Length, colour = Species)) +
  geom_point() +
  geom_smooth(method=lm, se=F) +
  facet_grid(family~Species) +
  geom_text(aes(label=eq, x=1.5, y=6)) +
  theme_linedraw() 

我尝试使用给定的解决方案here,但它对我不起作用

ggplot(iris4, aes(x = Petal.Width, y = Petal.Length, colour = Species)) +
  geom_point() +
  geom_smooth(method=lm, se=F) +
  facet_grid(family~Species) +
  geom_text(aes(label=iris4$eq, x=1.5, y=6), data = data.frame()) +
  theme_linedraw() 

使用注释,我有一条错误消息(我理解问题,但我无法解决)

ggplot(iris4, aes(x = Petal.Width, y = Petal.Length, colour = Species)) +
  geom_point() +
  geom_smooth(method=lm, se=F) +
  facet_grid(family~Species) +
  annotate("text", x = 1.5, y = 6, label = iris4$eq) +
  theme_linedraw() 

如果我引用coefs表(长度比facet长),则方程式不再匹配

ggplot(iris4, aes(x = Petal.Width, y = Petal.Length, colour = Species)) +
  geom_point() +
  geom_smooth(method=lm, se=F) +
  facet_grid(family~Species) +
  annotate("text", x = 1.5, y = 6, label = coefs$eq) +
  theme_linedraw() 

任何人都有解决方案吗?

非常感谢!

1 个答案:

答案 0 :(得分:0)

问题是ggplot正在为数据中的每一行打印文本。你可以通过只给每个标签一行来阻止它。在这里,我使用dplyr::distinct执行此操作,但还有其他方法

ggplot(iris4, aes(x = Petal.Width, y = Petal.Length, colour = Species)) +
  geom_point() +
  geom_smooth(method=lm, se=F) +
  facet_grid(family~Species) +
  geom_text(aes(label=eq, x=1.5, y=6), data = dplyr::distinct(iris4, eq, .keep_all = TRUE)) +
  theme_linedraw()