ggplot2：合并 geom_line、geom_point 和 geom_bar 的图例
ggplot2: merge legends for geom_line, geom_point, and geom_bar
在 ggplot2 情节中，我将 geom_line 和 geom_point 与 geom_bar 合并，但在将图例合并到一个框中时遇到问题。
基本情节的代码如下。使用的数据再往下
# Packages
library(ggplot2)
library(scales)
# Basic Plot
ggplot(data = df1, aes(x = Year, y = value, group = variable,
colour = variable, shape = variable)) +
geom_line() +
geom_point(size = 3) +
geom_bar(data = df2, aes(x = Year, y = value, fill = variable),
stat = "identity", alpha = 0.8) +
ylab("Current Account Transactions (Billion $)") +
xlab(NULL) +
theme_bw(14) +
scale_x_discrete(breaks = seq(1999, 2013, by = 2)) +
scale_y_continuous(labels = dollar, limits = c(-1, 4),
breaks = seq(-1, 4, by = .5)) +
geom_hline(yintercept = 0) +
theme(legend.key = element_blank(),
legend.background = element_rect(colour = 'black', fill = 'white'),
legend.position = "top", legend.title = element_blank()) +
guides(col = guide_legend(ncol = 1), fill = NULL, colour = NULL)
我的objective是把图例合并在一起。出于某种原因，"Balance on current account" 出现在顶部图例中（我不明白为什么），而 "Exports" 和 "Imports" 图例被黑色背景和缺失的形状弄乱了。
如果我将 fill 放在 aes 之外，我可以获得 "Imports" 和 "Exports" 的图例以正确的形状和颜色显示，并且没有黑色背景，但后来我失去了 "Balance on current account."
的 fill 图例
我以前用过的一个小技巧，也就是用scale_colour_manual、scale_shape_manual和scale_fill_manual（也许还有scale_alpha）好像不行这里。让它工作会很好。但是请注意，据我所知，使用这个技巧，必须手动指定颜色、形状和填充，我真的不想这样做，因为我对默认 colours/shapes/fills 非常满意。
我通常会这样做，但它不起作用：
library(RColorBrewer)
cols <- colorRampPalette(brewer.pal(9, "Set1"))(3)
last_plot() + scale_colour_manual(name = "legend", values = cols) +
scale_shape_manual(name = "legend", values = c(0,2,1)) +
scale_fill_manual(name = "legend", values = "darkred")
在上面我没有指定标签，因为在我的问题中我将处理大量数据并且手动指定标签是不切实际的。我希望 ggplot2 使用默认标签。出于同样的原因，我想使用默认的colors/shapes/fills。
其他地方也报告了类似的困难，例如这里Construct a manual legend for a complicated plot，但我还没有设法解决我的问题。
有什么想法吗？
# Data
df1 <- structure(list(Year = structure(c(1L, 2L, 3L, 4L, 5L, 6L, 7L,
8L, 9L, 10L, 11L, 12L, 13L, 14L, 15L, 1L, 2L, 3L, 4L, 5L, 6L,
7L, 8L, 9L, 10L, 11L, 12L, 13L, 14L, 15L), .Label = c("1999",
"2000", "2001", "2002", "2003", "2004", "2005", "2006", "2007",
"2008", "2009", "2010", "2011", "2012", "2013"), class = "factor"),
variable = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L,
1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L,
2L, 2L, 2L, 2L, 2L, 2L), .Label = c("Exports of goods and services",
"Imports of goods and services"), class = "factor"), value = c(1.304557,
1.471532, 1.345165, 1.31879, 1.409053, 1.642291, 1.895983,
2.222124, 2.569492, 2.751949, 2.285922, 2.630799, 2.987571,
3.08526, 3.178744, 1.600087, 1.882288, 1.740493, 1.776877,
1.930395, 2.276059, 2.641418, 3.028851, 3.288135, 3.43859,
2.666714, 3.074729, 3.446914, 3.546009, 3.578998)), .Names = c("Year",
"variable", "value"), row.names = c(NA, -30L), class = "data.frame")
df2 <- structure(list(Year = structure(1:15, .Label = c("1999", "2000 ",
"2001", "2002 ", "2003", "2004 ", "2005", "2006 ", "2007", "2008 ",
"2009", "2010 ", "2011", "2012 ", "2013"), class = "factor"),
variable = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L,
1L, 1L, 1L, 1L, 1L, 1L), .Label = "Balance on current account", class = "factor"),
value = c(-0.29553, -0.410756, -0.395328, -0.458087, -0.521342,
-0.633768, -0.745434, -0.806726, -0.718643, -0.686641, -0.380792,
-0.44393, -0.459344, -0.460749, -0.400254)), .Names = c("Year",
"variable", "value"), row.names = c(NA, -15L), class = "data.frame")
编辑
在发布我的问题并阅读 Scott 的回答后，我尝试了另一种方法。它在某些方面更接近预期结果，但在其他方面更接近预期结果。这个想法是将数据帧合并到一个数据帧中，并将 colour/shape/fill 传递给第一个 ggplot 调用中的 aes 。这个问题是我在图例中得到了一个不需要的 'slash' 。如果不移除所有颜色，我无法移除斜线。我马上提到的这种方法的另一个问题是我需要手动指定一堆东西，而我想尽可能保留默认值。
df <- rbind(df1, df2)
ggplot(data = df, aes(x = Year, y = value, group = variable, colour = variable,
shape = variable, fill = variable)) +
geom_line(data = subset(df, variable %in% c("Exports of goods and services", "Imports of goods and services"))) +
geom_point(data = subset(df, variable %in% c("Exports of goods and services", "Imports of goods and services")), size = 3) +
geom_bar(data = subset(df, variable %in% c("Balance on current account")), aes(x = Year, y = value, fill = variable),
stat = "identity", alpha = 0.8)
cols <- c(NA, "darkgreen", "darkblue")
last_plot() + scale_colour_manual(name = "legend", values = cols) +
scale_shape_manual(name = "legend", values = c(32, 15, 17)) +
scale_fill_manual(name = "legend", values = c("orange", NA, NA)) +
ylab("Current Account Transactions (Billion $)") +
xlab(NULL) +
theme_bw(14) + scale_x_discrete(breaks = seq(1999, 2013, by = 2)) +
scale_y_continuous(labels = dollar, limits = c(-1, 4), breaks = seq(-1, 4, by = .5)) +
geom_hline(yintercept = 0) +
theme(legend.key = element_blank(), legend.background = element_rect(colour = 'black', fill = 'white'), legend.position = "top", legend.title = element_blank()) +
guides(col = guide_legend(ncol = 1))
添加 + guides(fill = guide_legend(override.aes = list(colour = NULL))) 会删除斜线，但也会删除 darkgreen/darkblue 颜色（它会保留橙色填充）。
要消除 "Balance on current account" 出现在顶部图例中，您可以将 group、colour 和 shape 美学移出父 ggplot() 调用并适当地放入 geom_line() 和 geom_point()。这可以具体控制将哪些美学应用于共享变量名称的两个数据集。
ggplot(data = df1, aes(x = Year, y = value)) +
geom_line(aes(group = variable, colour = variable)) +
geom_point(aes(shape = variable, colour = variable), size = 3) +
geom_bar(data = df2, aes(x = Year, y = value, fill = variable),
stat = "identity", position = 'identity', alpha = 0.8, guide = 'none') +
ylab("Current Account Transactions (Billion $)") +
xlab(NULL) +
theme_bw(14) +
scale_x_discrete(breaks = seq(1999, 2013, by = 2)) +
scale_y_continuous(labels = dollar, limits = c(-1, 4),
breaks = seq(-1, 4, by = .5)) +
geom_hline(yintercept = 0) +
guides(col = guide_legend(ncol = 1)) +
theme(legend.key = element_blank(),
legend.background = element_rect(colour = 'black', fill = 'white'),
legend.position = "top", legend.title = element_blank(),
legend.box.just = "left")
这个答案有一些缺点。举几个例子：1) 两个独立的图例仍然存在，如果您决定不将它们装箱（例如，不设置 legend.background，则可以伪装）。 2) 从顶部图例中删除 df2 变量意味着它不会使用第一个默认颜色（如前所述，纯属巧合），所以现在 "Balance..." 和 "Exports..." 都显示为粉红色，因为填充图例回收默认色标。
在 ggplot2 情节中，我将 geom_line 和 geom_point 与 geom_bar 合并，但在将图例合并到一个框中时遇到问题。
基本情节的代码如下。使用的数据再往下
# Packages
library(ggplot2)
library(scales)
# Basic Plot
ggplot(data = df1, aes(x = Year, y = value, group = variable,
colour = variable, shape = variable)) +
geom_line() +
geom_point(size = 3) +
geom_bar(data = df2, aes(x = Year, y = value, fill = variable),
stat = "identity", alpha = 0.8) +
ylab("Current Account Transactions (Billion $)") +
xlab(NULL) +
theme_bw(14) +
scale_x_discrete(breaks = seq(1999, 2013, by = 2)) +
scale_y_continuous(labels = dollar, limits = c(-1, 4),
breaks = seq(-1, 4, by = .5)) +
geom_hline(yintercept = 0) +
theme(legend.key = element_blank(),
legend.background = element_rect(colour = 'black', fill = 'white'),
legend.position = "top", legend.title = element_blank()) +
guides(col = guide_legend(ncol = 1), fill = NULL, colour = NULL)
我的objective是把图例合并在一起。出于某种原因，"Balance on current account" 出现在顶部图例中（我不明白为什么），而 "Exports" 和 "Imports" 图例被黑色背景和缺失的形状弄乱了。
如果我将 fill 放在 aes 之外，我可以获得 "Imports" 和 "Exports" 的图例以正确的形状和颜色显示，并且没有黑色背景，但后来我失去了 "Balance on current account."
fill 图例
我以前用过的一个小技巧，也就是用scale_colour_manual、scale_shape_manual和scale_fill_manual（也许还有scale_alpha）好像不行这里。让它工作会很好。但是请注意，据我所知，使用这个技巧，必须手动指定颜色、形状和填充，我真的不想这样做，因为我对默认 colours/shapes/fills 非常满意。
我通常会这样做，但它不起作用：
library(RColorBrewer)
cols <- colorRampPalette(brewer.pal(9, "Set1"))(3)
last_plot() + scale_colour_manual(name = "legend", values = cols) +
scale_shape_manual(name = "legend", values = c(0,2,1)) +
scale_fill_manual(name = "legend", values = "darkred")
在上面我没有指定标签，因为在我的问题中我将处理大量数据并且手动指定标签是不切实际的。我希望 ggplot2 使用默认标签。出于同样的原因，我想使用默认的colors/shapes/fills。
其他地方也报告了类似的困难，例如这里Construct a manual legend for a complicated plot，但我还没有设法解决我的问题。
有什么想法吗？
# Data
df1 <- structure(list(Year = structure(c(1L, 2L, 3L, 4L, 5L, 6L, 7L,
8L, 9L, 10L, 11L, 12L, 13L, 14L, 15L, 1L, 2L, 3L, 4L, 5L, 6L,
7L, 8L, 9L, 10L, 11L, 12L, 13L, 14L, 15L), .Label = c("1999",
"2000", "2001", "2002", "2003", "2004", "2005", "2006", "2007",
"2008", "2009", "2010", "2011", "2012", "2013"), class = "factor"),
variable = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L,
1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L,
2L, 2L, 2L, 2L, 2L, 2L), .Label = c("Exports of goods and services",
"Imports of goods and services"), class = "factor"), value = c(1.304557,
1.471532, 1.345165, 1.31879, 1.409053, 1.642291, 1.895983,
2.222124, 2.569492, 2.751949, 2.285922, 2.630799, 2.987571,
3.08526, 3.178744, 1.600087, 1.882288, 1.740493, 1.776877,
1.930395, 2.276059, 2.641418, 3.028851, 3.288135, 3.43859,
2.666714, 3.074729, 3.446914, 3.546009, 3.578998)), .Names = c("Year",
"variable", "value"), row.names = c(NA, -30L), class = "data.frame")
df2 <- structure(list(Year = structure(1:15, .Label = c("1999", "2000 ",
"2001", "2002 ", "2003", "2004 ", "2005", "2006 ", "2007", "2008 ",
"2009", "2010 ", "2011", "2012 ", "2013"), class = "factor"),
variable = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L,
1L, 1L, 1L, 1L, 1L, 1L), .Label = "Balance on current account", class = "factor"),
value = c(-0.29553, -0.410756, -0.395328, -0.458087, -0.521342,
-0.633768, -0.745434, -0.806726, -0.718643, -0.686641, -0.380792,
-0.44393, -0.459344, -0.460749, -0.400254)), .Names = c("Year",
"variable", "value"), row.names = c(NA, -15L), class = "data.frame")
编辑
在发布我的问题并阅读 Scott 的回答后，我尝试了另一种方法。它在某些方面更接近预期结果，但在其他方面更接近预期结果。这个想法是将数据帧合并到一个数据帧中，并将 colour/shape/fill 传递给第一个 ggplot 调用中的 aes 。这个问题是我在图例中得到了一个不需要的 'slash' 。如果不移除所有颜色，我无法移除斜线。我马上提到的这种方法的另一个问题是我需要手动指定一堆东西，而我想尽可能保留默认值。
df <- rbind(df1, df2)
ggplot(data = df, aes(x = Year, y = value, group = variable, colour = variable,
shape = variable, fill = variable)) +
geom_line(data = subset(df, variable %in% c("Exports of goods and services", "Imports of goods and services"))) +
geom_point(data = subset(df, variable %in% c("Exports of goods and services", "Imports of goods and services")), size = 3) +
geom_bar(data = subset(df, variable %in% c("Balance on current account")), aes(x = Year, y = value, fill = variable),
stat = "identity", alpha = 0.8)
cols <- c(NA, "darkgreen", "darkblue")
last_plot() + scale_colour_manual(name = "legend", values = cols) +
scale_shape_manual(name = "legend", values = c(32, 15, 17)) +
scale_fill_manual(name = "legend", values = c("orange", NA, NA)) +
ylab("Current Account Transactions (Billion $)") +
xlab(NULL) +
theme_bw(14) + scale_x_discrete(breaks = seq(1999, 2013, by = 2)) +
scale_y_continuous(labels = dollar, limits = c(-1, 4), breaks = seq(-1, 4, by = .5)) +
geom_hline(yintercept = 0) +
theme(legend.key = element_blank(), legend.background = element_rect(colour = 'black', fill = 'white'), legend.position = "top", legend.title = element_blank()) +
guides(col = guide_legend(ncol = 1))
添加 + guides(fill = guide_legend(override.aes = list(colour = NULL))) 会删除斜线，但也会删除 darkgreen/darkblue 颜色（它会保留橙色填充）。
要消除 "Balance on current account" 出现在顶部图例中，您可以将 group、colour 和 shape 美学移出父 ggplot() 调用并适当地放入 geom_line() 和 geom_point()。这可以具体控制将哪些美学应用于共享变量名称的两个数据集。
ggplot(data = df1, aes(x = Year, y = value)) +
geom_line(aes(group = variable, colour = variable)) +
geom_point(aes(shape = variable, colour = variable), size = 3) +
geom_bar(data = df2, aes(x = Year, y = value, fill = variable),
stat = "identity", position = 'identity', alpha = 0.8, guide = 'none') +
ylab("Current Account Transactions (Billion $)") +
xlab(NULL) +
theme_bw(14) +
scale_x_discrete(breaks = seq(1999, 2013, by = 2)) +
scale_y_continuous(labels = dollar, limits = c(-1, 4),
breaks = seq(-1, 4, by = .5)) +
geom_hline(yintercept = 0) +
guides(col = guide_legend(ncol = 1)) +
theme(legend.key = element_blank(),
legend.background = element_rect(colour = 'black', fill = 'white'),
legend.position = "top", legend.title = element_blank(),
legend.box.just = "left")
这个答案有一些缺点。举几个例子：1) 两个独立的图例仍然存在，如果您决定不将它们装箱（例如，不设置 legend.background，则可以伪装）。 2) 从顶部图例中删除 df2 变量意味着它不会使用第一个默认颜色（如前所述，纯属巧合），所以现在 "Balance..." 和 "Exports..." 都显示为粉红色，因为填充图例回收默认色标。