如何在图例中添加图例? [英] How to add a legend to hline?

问题描述

我想在图样中添加一个图例.

I'd like to add a legend to hline plot.

我的子集的头看起来像这样

The head of my subset looks like this

Site       Date    Al
1   Bo6 2014-10-07 152.1
2   Bo1 2014-10-07 157.3
3   Bo3 2014-10-07 207.1
4   Bo4 2014-10-07 184.3
5   Bo5 2014-10-07  23.2
13  Bo6 2014-10-14  96.8

我的代码如下:

require(ggplot2)
require(reshape2)
require(magrittr)
require(dplyr)
require(tidyr)
setwd("~/Documents/Results")
mydata <- read.csv("Metals sheet Rwosnb5.csv")
mydata <- read.csv("Metals sheet Rwosnb5.csv")
L <- subset(mydata, Site =="Bo1"| Site == "Bo2"| Site == "Bo3"| Site ==          "Bo4"| Site == "Bo5" | Site == "Bo6", select = c(Site,Date,Al))
L$Date <- as.Date(L$Date, "%d/%m/%Y")
I <- ggplot(data=L, aes(x=Date, y=Al, colour=Site)) +
  geom_point() + 
  labs(title = "Total Al in the Barlwyd and Bowydd in Pant-yr-afon    sites B4-B9
   2014-2015.", x = "Month 2014/2015",
   y = "Total concentration (mg/L)") +
  scale_y_continuous(limits = c(0, 500)) +
  scale_x_date(date_breaks = "1 month", date_labels = "%m")
I + geom_hline(aes(yintercept= 10),  linetype = 2, colour= 'red',   show.legend =TRUE) +
  geom_hline(aes(yintercept= 75.5), linetype = 2, colour= 'blue', show.legend = TRUE)

由于某些原因，图例不起作用-图例有六个站点，其中有一条线.理想情况下，我想要一个标题=限制的图例 标签1(10)= NRW限值，标签2(75.5)=地球化学图谱限值.

For some reason the legend does not work -- the legend has the six sites with a line through them. I would ideally like a legend with title = limit and Label 1 (10) = NRW limit and label 2 (75.5)= Geochemical atlas limit.

推荐答案

您可以使用linetype美感为水平线制作单独的图例，而不必将其添加到现有图例中.

You can use the linetype aesthetic to make a separate legend for the horizontal lines rather than adding them to the existing legend.

为此，我们可以将linetype移到aes内，同时仍映射到常量.我用了你想要的标签作为常数.可以在scale_linetype_manual中设置图例名称和使用的线型.我删除了show.legend = TRUE，以使行不出现在其他图例中.图例颜色在override.aes中固定.

To do this we can move linetype inside aes while still mapping to a constant. I used your desired labels as the constant. The legend name and the line type used can be set in scale_linetype_manual. I remove show.legend = TRUE to keep the lines out of the other legend. The legend colors are fixed in override.aes.

I + geom_hline(aes(yintercept= 10, linetype = "NRW limit"), colour= 'red') +
    geom_hline(aes(yintercept= 75.5, linetype = "Geochemical atlas limit"), colour= 'blue') +
    scale_linetype_manual(name = "limit", values = c(2, 2), 
                      guide = guide_legend(override.aes = list(color = c("blue", "red"))))

这篇关于如何在图例中添加图例?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！