如何在不更改 R 中的图例颜色的情况下使用多个符号、颜色和填充 ggmap？

Question

我正在使用 ggmap 绘制海洋中的一些填充点，但它们重叠，所以我使用 colour=black 给它们一个轮廓。当我使用 pch=21 时，图例不会改变，并且点会像我想要的那样用黑色勾勒出来。但是，我也试图在地图上获得 3 个不同的符号。当我指定不同的符号时，我在图例中的点都变成黑色。

这是一些示例数据和代码，我用来获取图例正确但符号错误的地图

#library
library(ggmap)
library(mapdata)
library(ggplot2)

#sample

mapoc_temp = data.frame(longitude= c(-64.5, -63.1, -62.4, -62.2, -66.0, -61.9), 
                                    latitude= c(42.7, 44.8, 45.8, 45.6, 43.0, 40.2),
                                    Zone = sample(c(1,4,6,7), 6, replace = T),
                                    location = sample(c(1,2,3), 6, replace = T))

#map
canada = map_data("worldHires")
ggplot(data = canada) +
  borders("world", xlim = c(-130, -60), ylim = c(20, 50), colour = "black", fill = "grey50") +
  geom_polygon(data = canada, aes(x=long, y = lat, group = group), fill = "grey50") +
  #coordinates of my map
  coord_sf(xlim=c(-84, -41), ylim=c(24,51), expand = FALSE) +
  #map the receiver locations
  geom_point(data = mapoc_temp,
             mapping = aes(x = longitude, 
                           y = latitude,
                           fill = Zone), 
             pch = 21,
             size = 15, colour = "black") +
  #fill the zones 
  scale_color_manual(values=c("#01579B", "#4FC3F7", "#ffa600", "#ff6361")) +
  scale_fill_manual(values=c("#01579B", "#4FC3F7", "#ffa600", "#ff6361"))

这就是地图的样子

当我尝试添加符号时，我得到了正确的符号，但我的图例不再正确。下面是代码和图片。

ggplot(data = canada) +
  borders("world", xlim = c(-130, -60), ylim = c(20, 50), colour = "black", fill = "grey50") +
  geom_polygon(data = canada, aes(x=long, y = lat, group = group), fill = "grey50") +
  #coordinates of my map
  coord_sf(xlim=c(-84, -41), ylim=c(24,51), expand = FALSE) +
  #map the receiver locations
  geom_point(data = mapoc_temp,
             mapping = aes(x = longitude, 
                           y = latitude,
                           fill = as.factor(Zone)), 
             pch = pch = if_else(mapoc_temp$location == 1,25,
                                 if_else(mapoc_temp$location == 3, 23, 21)),
             size = 15, colour = "black") +
  scale_x_continuous(label = abs) +
  scale_y_continuous(label = abs) +
  #fill the zones in with viridis
  scale_color_manual(values=c("#01579B", "#4FC3F7", "#ffa600", "#ff6361")) +
  scale_fill_manual(values=c("#01579B", "#4FC3F7", "#ffa600", "#ff6361"))

有谁知道如何修复第二张图片中的图例，使点的颜色正确？我不需要图例中的符号

Answer 1

实际上，您的问题是由此处描述的错误引起的：https://github.com/tidyverse/ggplot2/issues/2322。

要过去，你可以这样做：

ggplot(data = canada) +
  borders("world", xlim = c(-130, -60), ylim = c(20, 50), colour = "black", fill = "grey50") +
  geom_polygon(data = canada, aes(x=long, y = lat, group = group), fill = "grey50") +
  #coordinates of my map
  coord_sf(xlim=c(-84, -41), ylim=c(24,51), expand = FALSE) +
  #map the receiver locations
  geom_point(inherit.aes = FALSE, data = mapoc_temp,
             mapping = aes(x = longitude, 
                           y = latitude,
                           fill = factor(Zone),
                           shape = factor(location)),
             size = 5) +
  scale_x_continuous(label = abs) +
  scale_y_continuous(label = abs) +
  #fill the zones in with viridis
  scale_fill_manual(name = "Zone", values=c("#01579B", "#4FC3F7", "#ffa600", "#ff6361"), breaks = c("1","4","6","7")) +
  scale_shape_manual(values = c("1" = 21, "2" = 22, "3" = 24))+
  guides(fill = guide_legend(override.aes=list(shape=21)), shape = FALSE)

如@Edward 所述，您可以通过添加 guides(shape = FALSE).

来摆脱 shape 图例

它是否回答了您的问题？

Answer 2

我没有你的数据，所以我将使用好的 ol' mtcars 数据集。诀窍是手动分配形状，否则 ggplot 会抱怨 "A continuous variable can not be mapped to shape".

mtcars$shape <- ifelse(mtcars$cyl==4, 21, ifelse(mtcars$cyl==6, 23, 25))

ggplot(mtcars, aes(wt, mpg)) + 
   geom_point(aes(fill = factor(cyl), shape=factor(cyl)), col="black", size=3) +
   scale_shape_manual(values=c(21,23,25))

对于您自己的数据，请尝试：

mapoc_temp$shape <- factor(mapoc_temp$location + 20)

geom_point(data = mapoc_temp,
           mapping = aes(x = longitude, 
                         y = latitude,
                         fill = factor(Zone),
                         shape= shape),
           size = 15, colour = "black") +
  scale_shape_manual(values=c(21,22,23)) + # Must be same length as unique location.
  guides(shape=FALSE) + # If you don't want an extra shape legend.
  guides(fill = guide_legend(override.aes=list(shape=21))) # A necessary fudge

如何在不更改 R 中的图例颜色的情况下使用多个符号、颜色和填充 ggmap？

How to use several symbols, colour, and fill in ggmap without changing the legend colour in R?

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ggmap