为复杂图构建手动图例 [英] Construct a manual legend for a complicated plot

问题描述

我无法弄清楚如何为此图手动设置图例.我真正想要的只是右侧的一个简单图例，它使用三种颜色并在每种颜色旁边都有一个名称.

I cannot figure out how to manually set up a legend for this plot. All I really want is a simple legend to the right that uses the three colors and has a name next to each.

当前代码如下:

a <-c("S1","S2","S3","S4","S5","S6","S7","S8","S9") #names
b <-c(0.23,0.26,0.55,0.56,0.36,0.23,0.18,0.06,0.04) #mean t0
c <-c(0.64,0.6,0.81,1.4,0.89,0.55,0.48,0.22,0.09) #mean t1
d <-c(0.20,0.23,0.52,0.53,0.33,0.20,0.15,0.04,0.03) #SD low t0
e <-c(0.26,0.29,0.58,.59,0.39,0.26,0.21,0.08,0.05) #SD high t0
f <-c(0.67,0.63,0.86,1.44,0.93,0.59,0.51,0.25,0.10) #SD high t1
g <-c(0.61,0.57,0.78,1.36,0.85,0.53,0.45,0.19,0.08) #SD low t1
h <-c(0.41,0.34,0.26,0.84,0.53,0.32,0.30,0.16,0.05) #absolute change

data <- data.frame(a,b,c,d,e,f,g,h)

ggplot(data=data,aes(a)) + 
  geom_bar(stat="identity", aes(y=h),fill="#62c76b",colour="#333333")+ #green
  geom_line(aes(y=b,group=1),size=1.0,colour="#f04546") +   #red
  geom_point(aes(y=b),size=3, colour="#f04546") +           #red
  geom_errorbar(aes(ymin=d, ymax=e), colour="#f04546", width=0.1, size=.8) + 
  geom_line(aes(y=c,group=1),size=1.0,colour="#3591d1") +   #blue 
  geom_point(aes(y=c),size=3, colour="#3591d1") +           #blue
  geom_errorbar(aes(ymin=f, ymax=g), colour="#3591d1", width=0.1, size=.8) + 
  ylab("Symptom severity") + xlab("PHQ-9 symptoms") +
  ylim(0,1.6) +
  theme_bw() +
  theme(axis.title.x = element_text(size = 15, vjust=-.2)) +
  theme(axis.title.y = element_text(size = 15, vjust=0.3))

推荐答案

您需要将属性映射到美学(aes 语句中的颜色)以生成图例.

You need to map attributes to aesthetics (colours within the aes statement) to produce a legend.

cols <- c("LINE1"="#f04546","LINE2"="#3591d1","BAR"="#62c76b")
ggplot(data=data,aes(x=a)) + 
  geom_bar(stat="identity", aes(y=h, fill = "BAR"),colour="#333333")+ #green
  geom_line(aes(y=b,group=1, colour="LINE1"),size=1.0) +   #red
  geom_point(aes(y=b, colour="LINE1"),size=3) +           #red
  geom_errorbar(aes(ymin=d, ymax=e, colour="LINE1"), width=0.1, size=.8) + 
  geom_line(aes(y=c,group=1,colour="LINE2"),size=1.0) +   #blue 
  geom_point(aes(y=c,colour="LINE2"),size=3) +           #blue
  geom_errorbar(aes(ymin=f, ymax=g,colour="LINE2"), width=0.1, size=.8) + 
  scale_colour_manual(name="Error Bars",values=cols) + scale_fill_manual(name="Bar",values=cols) +
  ylab("Symptom severity") + xlab("PHQ-9 symptoms") +
  ylim(0,1.6) +
  theme_bw() +
  theme(axis.title.x = element_text(size = 15, vjust=-.2)) +
  theme(axis.title.y = element_text(size = 15, vjust=0.3))

我了解 Roland 的来源，但由于这只有 3 个属性，并且叠加条和误差条会引起并发症，因此将数据保留为宽格式可能是合理的.使用 geom_pointrange 可以稍微降低复杂性.

I understand where Roland is coming from, but since this is only 3 attributes, and complications arise from superimposing bars and error bars this may be reasonable to leave the data in wide format like it is. It could be slightly reduced in complexity by using geom_pointrange.

要更改原始错误条图例的背景颜色，请在图中添加 + theme(legend.key = element_rect(fill = "white",colour = "white"))规格.要合并不同的图例，您通常需要对所有元素进行一致的映射，但它目前正在为我生成黑色背景的工件.我以为 guide = guide_legend(fill = NULL,colour = NULL) 会将图例的背景设置为 null，但事实并非如此.也许值得另一个问题.

To change the background color for the error bars legend in the original, add + theme(legend.key = element_rect(fill = "white",colour = "white")) to the plot specification. To merge different legends, you typically need to have a consistent mapping for all elements, but it is currently producing an artifact of a black background for me. I thought guide = guide_legend(fill = NULL,colour = NULL) would set the background to null for the legend, but it did not. Perhaps worth another question.

ggplot(data=data,aes(x=a)) + 
  geom_bar(stat="identity", aes(y=h,fill = "BAR", colour="BAR"))+ #green
  geom_line(aes(y=b,group=1, colour="LINE1"),size=1.0) +   #red
  geom_point(aes(y=b, colour="LINE1", fill="LINE1"),size=3) +           #red
  geom_errorbar(aes(ymin=d, ymax=e, colour="LINE1"), width=0.1, size=.8) + 
  geom_line(aes(y=c,group=1,colour="LINE2"),size=1.0) +   #blue 
  geom_point(aes(y=c,colour="LINE2", fill="LINE2"),size=3) +           #blue
  geom_errorbar(aes(ymin=f, ymax=g,colour="LINE2"), width=0.1, size=.8) + 
  scale_colour_manual(name="Error Bars",values=cols, guide = guide_legend(fill = NULL,colour = NULL)) + 
  scale_fill_manual(name="Bar",values=cols, guide="none") +
  ylab("Symptom severity") + xlab("PHQ-9 symptoms") +
  ylim(0,1.6) +
  theme_bw() +
  theme(axis.title.x = element_text(size = 15, vjust=-.2)) +
  theme(axis.title.y = element_text(size = 15, vjust=0.3))

要去除图例中的黑色背景，您需要对 guide_legend 使用 override.aes 参数.这样做的目的是让您指定可能未正确分配的图例的特定方面.

To get rid of the black background in the legend, you need to use the override.aes argument to the guide_legend. The purpose of this is to let you specify a particular aspect of the legend which may not be being assigned correctly.

ggplot(data=data,aes(x=a)) + 
  geom_bar(stat="identity", aes(y=h,fill = "BAR", colour="BAR"))+ #green
  geom_line(aes(y=b,group=1, colour="LINE1"),size=1.0) +   #red
  geom_point(aes(y=b, colour="LINE1", fill="LINE1"),size=3) +           #red
  geom_errorbar(aes(ymin=d, ymax=e, colour="LINE1"), width=0.1, size=.8) + 
  geom_line(aes(y=c,group=1,colour="LINE2"),size=1.0) +   #blue 
  geom_point(aes(y=c,colour="LINE2", fill="LINE2"),size=3) +           #blue
  geom_errorbar(aes(ymin=f, ymax=g,colour="LINE2"), width=0.1, size=.8) + 
  scale_colour_manual(name="Error Bars",values=cols, 
                      guide = guide_legend(override.aes=aes(fill=NA))) + 
  scale_fill_manual(name="Bar",values=cols, guide="none") +
  ylab("Symptom severity") + xlab("PHQ-9 symptoms") +
  ylim(0,1.6) +
  theme_bw() +
  theme(axis.title.x = element_text(size = 15, vjust=-.2)) +
  theme(axis.title.y = element_text(size = 15, vjust=0.3))

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