为什么在世界映射时我会在 ggplot 中得到不同的图例？

Question

我正在尝试使用 ggplot2 和地图绘制以下 DF。我对情节本身没有问题，但两个传说看起来不同。我尝试了不同的组合，包括休息、设置限制，但两者仍然不同。我需要的是两个图的图例相同，值具有相同的颜色。

我尝试了以下方法。但这两个传说并不匹配。在 DF2 的情节中，这似乎对我有用，但在 DF1 中，传说从 100 开始，颜色不匹配。有人可以指出一个实用的解决方案吗？

library(maps)
library(ggplot2)


ggplot(data = DF1, mapping = aes(x = long, y = lat, group = group)) + 
  coord_fixed(1.3) +
  geom_polygon(aes(fill = V1), col="black") +
  scale_fill_gradientn(colours = rev(rainbow(20)),guide="colourbar",
 breaks = c(1,100, 1000, 10000,100000, 1000000),
trans = "log10")
                        +
  ggtitle("Title(log10)")

**-Plot DF2**


ggplot(data = DF2, mapping = aes(x = long, y = lat, group = group)) + 
  coord_fixed(1.3) +
  geom_polygon(aes(fill = V2), col="black") +
  scale_fill_gradientn(colours = rev(rainbow(20)),guide="colourbar",
 breaks = c(1,100, 1000, 10000,100000, 1000000),
trans = "log10")
                        +
  ggtitle("TitleDF2(log10)")

我的数据：

DF1
structure(list(long = c(55.1921882629395, 55.1940422058105, 55.1858367919922, 
55.1194343566895, 55.1042976379395, 55.0250015258789, 54.9982452392578, 
54.9224586486816, 54.8048820495605, 54.6522483825684, 54.4716796875, 
54.2701187133789, 54.0545883178711, 53.8321304321289, 53.6095695495605, 
53.39404296875, 53.1923828125, 53.0119132995605, 52.8592796325684, 
52.7416000366211, 52.6659202575684), lat = c(22.9229507446289, 
22.8500003814697, 22.7041015625, 22.6239261627197, 22.6214847564697, 
22.6311531066895, 22.6343746185303, 22.6436538696289, 22.6580085754395, 
22.6766605377197, 22.69873046875, 22.7233390808105, 22.7496585845947, 
22.7768058776855, 22.8040046691895, 22.830322265625, 22.8549308776855, 
22.8770008087158, 22.8956050872803, 22.9100093841553, 22.9192867279053
), group = c(15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 
15, 15, 15, 15, 15, 15, 15, 15, 15), order = 1049:1069, region = c("United Arab Emirates", 
"United Arab Emirates", "United Arab Emirates", "United Arab Emirates", 
"United Arab Emirates", "United Arab Emirates", "United Arab Emirates", 
"United Arab Emirates", "United Arab Emirates", "United Arab Emirates", 
"United Arab Emirates", "United Arab Emirates", "United Arab Emirates", 
"United Arab Emirates", "United Arab Emirates", "United Arab Emirates", 
"United Arab Emirates", "United Arab Emirates", "United Arab Emirates", 
"United Arab Emirates", "United Arab Emirates"), subregion = c(NA_character_, 
NA_character_, NA_character_, NA_character_, NA_character_, NA_character_, 
NA_character_, NA_character_, NA_character_, NA_character_, NA_character_, 
NA_character_, NA_character_, NA_character_, NA_character_, NA_character_, 
NA_character_, NA_character_, NA_character_, NA_character_, NA_character_
), V1 = c(12905.6580666578, 12905.6580666578, 
12905.6580666578, 12905.6580666578, 12905.6580666578, 12905.6580666578, 
12905.6580666578, 12905.6580666578, 12905.6580666578, 12905.6580666578, 
12905.6580666578, 12905.6580666578, 12905.6580666578, 12905.6580666578, 
12905.6580666578, 12905.6580666578, 12905.6580666578, 12905.6580666578, 
12905.6580666578, 12905.6580666578, 12905.6580666578)), row.names = 1010:1030, class = "data.frame")


DF2:
structure(list(long = c(-64.3834457397461, -64.6214828491211, 
-64.8529815673828, -64.8198776245117, -64.8043899536133, -64.8694839477539, 
-64.9169006347656, -65.0694351196289, -65.1333999633789, -65.15185546875, 
-65.1549758911133, -65.1278839111328, -65.0182647705078, -65.0070266723633, 
-65.05908203125, -64.9863739013672, -64.8980484008789, -64.6995162963867, 
-64.6224594116211, -64.5377502441406, -64.51171875), lat = c(-40.9224586486816, 
-40.8544921875, -40.8137664794922, -40.7932586669922, -40.7565460205078, 
-40.73583984375, -40.7313499450684, -40.8052749633789, -40.8806648254395, 
-40.9469757080078, -41.1056632995605, -41.23876953125, -41.56689453125, 
-41.7451171875, -41.9699211120605, -42.10205078125, -42.1618156433105, 
-42.2208023071289, -42.2610321044922, -42.2545890808105, -42.2702140808105
), group = c(20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 
20, 20, 20, 20, 20, 20, 20, 20, 20), order = 1554:1574, region = c("Argentina", 
"Argentina", "Argentina", "Argentina", "Argentina", "Argentina", 
"Argentina", "Argentina", "Argentina", "Argentina", "Argentina", 
"Argentina", "Argentina", "Argentina", "Argentina", "Argentina", 
"Argentina", "Argentina", "Argentina", "Argentina", "Argentina"
), subregion = c(NA_character_, NA_character_, NA_character_, 
NA_character_, NA_character_, NA_character_, NA_character_, NA_character_, 
NA_character_, NA_character_, NA_character_, NA_character_, NA_character_, 
NA_character_, NA_character_, NA_character_, NA_character_, NA_character_, 
NA_character_, NA_character_, NA_character_), V2 = c(5830.59840429215, 
5830.59840429215, 5830.59840429215, 5830.59840429215, 5830.59840429215, 
5830.59840429215, 5830.59840429215, 5830.59840429215, 5830.59840429215, 
5830.59840429215, 5830.59840429215, 5830.59840429215, 5830.59840429215, 
5830.59840429215, 5830.59840429215, 5830.59840429215, 5830.59840429215, 
5830.59840429215, 5830.59840429215, 5830.59840429215, 5830.59840429215
)), row.names = 1500:1520, class = "data.frame")

Answer 1

为了创建相同的外观，最安全的选择是使用分面图 - 您将获得两个图的连接图例。

我已经删除了 scale_ 中的 trans 参数...我可能会建议不要使用它。为了显示对数转换的数据，更安全的选择是先对数据进行对数转换，然后再绘制它。然后，您可以根据您的日志值设置中断（在这种情况下，1:6 相当于 10、100、1000 等）。我已经在 ggplot 中包含了一个直接执行此操作的选项。为了使效果更清晰，我稍微更改了 DF2 中的值。

library(ggplot2)
library(patchwork)

DF2$V2 <- DF2$V2/10 #just to make the difference more obvious

p1 <- 
  ggplot(data = DF1, mapping = aes(x = long, y = lat, group = group)) + 
  geom_polygon(aes(fill = log10(V1)), col="black") +
  scale_fill_gradientn(colours = rev(rainbow(20)),guide="colourbar",
                       breaks = c(1:6),
                       limits = c(1,6)) +
  ggtitle("Title(log10)")

p2 <- 
  ggplot(data = DF2, mapping = aes(x = long, y = lat, group = group)) + 
  geom_polygon(aes(fill = log10(V2)), col="black") +
  scale_fill_gradientn(colours = rev(rainbow(20)),guide="colourbar",
                       breaks = c(1:6),
                       limits = c(1,6)) +
  ggtitle("TitleDF2(log10)")

p1 + p2  

^{由reprex package (v0.3.0) 于 2020-05-12 创建}