以下代码会在图例中导致不需要的交叉效果。
ggplot() +
geom_vline(aes(xintercept=1,colour="vertical"), show.legend = NA) +
geom_hline(aes(yintercept=1,colour="horizontal"), show.legend = NA)
我读了几篇文章说添加show.legend = NA可以使这种效果消失，但这在我的情况下不起作用。
编辑： 为避免混淆，我不希望传说消失！我只是想让传说中的“十字架”消失，所以它应该显示如下项目：
和
我同意修复传说可能会很棘手。对于此示例，只需将show.legend = FALSE您不想要的 ONE 线放入即可。
library(ggplot2)
ggplot() +
geom_vline(aes(xintercept=1,colour="vertical"), show.legend = F) +
geom_hline(aes(yintercept=1,colour="horizontal"))
好的，这是尝试 2。它非常难看；它将两个传说塞进一个情节。它看起来非常接近你想要的。
library(ggplot2)
p1 <- ggplot() +
geom_vline(aes(xintercept=1,colour="vertical"))+
scale_color_manual(values = "#619CFF")
p2 <- ggplot()+
geom_hline(aes(yintercept=1,colour="horizontal"))
l1 <- cowplot::get_legend(p1)
l2 <- cowplot::get_legend(p2)
p3 <- ggplot() +
geom_vline(aes(xintercept=1,colour="vertical")) +
geom_hline(aes(yintercept=1,colour="horizontal"))+
theme(legend.position = "none")
l3 <- cowplot::plot_grid(l1, l2, ncol = 1, align = "v")
cowplot::plot_grid(p3, l3, nrow = 1, align = "h", rel_widths = c(1, 0.2))
如果您愿意深入了解底层网格（这总是很有趣），您可以手动删除指南中的垂直/水平条。
library(ggplot2)
library(grid)
library(gtable)
p <- ggplot() +
geom_vline(aes(xintercept = 1, color = "vertical")) +
geom_hline(aes(yintercept = 1, color = "horizontal"))
## First we create a gr(aphical)ob(ject) from the ggplot
g <- ggplotGrob(p)
## then we have to find out which child grob represents the legend
## the grob with the name "guide-box" is the one we are looking for
guide <- which(g$layout$name == "guide-box")
## the legend consists of guides and the background, go for the guides
guide_lines <- which(g$grobs[[guide]]$layout$name == "guides")
## the guides contain a lot of different grobs
## if you look at g$grobs[[guide]]$grobs[[guide_lines]] you will see
## 4 segments representing the 4 lines, these are at position 4-5 and 7-8
## segments at 4 and 7 are the vertical lines and 5 and 8 the horizontal lines
## NOTE: this you have to find out "manually", if you change the order in your
## ggplot the positions will be exactly switched
## one could write e function which checks whether a line is horizontal
## or vertical but this is most likely an overkill if this is for a
## single plot
## we can use gtable_filter to remove the unwanted lines
## it requires a regular expression formed by the names of the grobs to filter out
remove_pattern <- paste(g$grobs[[guide]]$grobs[[guide_lines]]$layout$name[c(4, 8)],
collapse = "|")
## write back the filtered gtable
g$grobs[[guide]]$grobs[[guide_lines]] <-
gtable_filter(g$grobs[[guide]]$grobs[[guide_lines]],
remove_pattern,
invert = TRUE)
## draw the grid
grid.draw(g)
https://github.com/tidyverse/ggplot2/issues/1267似乎有一个已知错误geom_vline
以那个 URL 上的代码为灵感，我想出了一些使用geom_linerange
thresholds <- data.frame(colour = "vertical", x = 1, ymin = 0.950, ymax = 1.050)
ggplot() +
geom_hline(aes(yintercept = 1, colour = "horizontal"), show.legend = NA) +
geom_linerange(data = thresholds,
mapping = aes(x = x, ymin = ymin, ymax = ymax, linetype = colour)) +
theme(legend.title = element_blank())
产生以下情节
