如何使用ggplot在facet_grid中设置不同的y轴比例？

Question

我有这个数据C_Em_df

structure(list(Driver = c("Crop agriculture", "Infrastructure", 
"Mining", "Mixed Agriculture", "Other land use", "Pasture", "Tree crops", 
"Water", "Crop agriculture", "Infrastructure", "Mining", "Mixed Agriculture", 
"Other land use", "Pasture", "Tree crops", "Water", "Crop agriculture", 
"Infrastructure", "Mining", "Mixed Agriculture", "Other land use", 
"Pasture", "Tree crops", "Water", "Crop agriculture", "Infrastructure", 
"Mining", "Mixed Agriculture", "Other land use", "Pasture", "Tree crops", 
"Water"), Period = c("1990-2000", "1990-2000", "1990-2000", "1990-2000", 
"1990-2000", "1990-2000", "1990-2000", "1990-2000", "1990-2000", 
"1990-2000", "1990-2000", "1990-2000", "1990-2000", "1990-2000", 
"1990-2000", "1990-2000", "2000-2005", "2000-2005", "2000-2005", 
"2000-2005", "2000-2005", "2000-2005", "2000-2005", "2000-2005", 
"2000-2005", "2000-2005", "2000-2005", "2000-2005", "2000-2005", 
"2000-2005", "2000-2005", "2000-2005"), Value = c(129536.358373574, 
14089.3660954917, 985.646531415156, 34951.5705930615, 75478.7796771996, 
1001024.77681633, 9673.51414314377, 51631.4446491193, 9.83294102032751, 
1.06950594852475, 0.0748191807457263, 2.65312948831128, 5.7294986378404, 
75.9865238911138, 0.73430421561273, 3.91927761752383, 273356.204972389, 
12040.5899468613, 607.505228212054, 45165.8223684273, 75748.9976185639, 
1221137.74328547, 8851.85933777376, 39629.016246337, 16.3048047540391, 
0.718181861746466, 0.0362357025480948, 2.69399377763239, 4.51818028644936, 
72.8368777437064, 0.527984496372407, 2.36374137750571), n = c("n = 1669", 
"n = 298", "n = 20", "n = 1355", "n = 1623", "n = 10986", "n = 316", 
"n = 466", "n = 1669", "n = 298", "n = 20", "n = 1355", "n = 1623", 
"n = 10986", "n = 316", "n = 466", "n = 783", "n = 151", "n = 7", 
"n = 925", "n = 851", "n = 6039", "n = 211", "n = 244", "n = 783", 
"n = 151", "n = 7", "n = 925", "n = 851", "n = 6039", "n = 211", 
"n = 244"), Type = c("Sum", "Sum", "Sum", "Sum", "Sum", "Sum", 
"Sum", "Sum", "Percentage", "Percentage", "Percentage", "Percentage", 
"Percentage", "Percentage", "Percentage", "Percentage", "Sum", 
"Sum", "Sum", "Sum", "Sum", "Sum", "Sum", "Sum", "Percentage", 
"Percentage", "Percentage", "Percentage", "Percentage", "Percentage", 
"Percentage", "Percentage")), .Names = c("Driver", "Period", 
"Value", "n", "Type"), row.names = c("1", "3", "5", "7", "9", 
"11", "13", "15", "12", "31", "51", "71", "91", "111", "131", 
"151", "2", "4", "6", "8", "10", "122", "14", "16", "21", "41", 
"61", "81", "101", "121", "141", "161"), class = "data.frame")

我想在ggplot中使用参数facet_grid在同一窗口中绘制一个绝对值（ Sum ）的图表和一个百分比值（ Percentage ）的图表。 为此，我需要在两个图中具有两个不同的y轴比例，以及两个不同的y轴标题。 我已经设法完成下面的代码行，但是无法真正得到我想要的。

g <- ggplot(C_Em_df, aes(x = Driver, y = Value, fill = Period, width = .85)) +
  facet_grid(Type~., scales="free")+
geom_bar(position = "dodge", stat = "identity") +
  labs(x = "", y = "Carbon emission (T/Year)") +
  theme(axis.text = element_text(size = 16),
        axis.title = element_text(size = 20), 
        legend.title = element_text(size = 20, face = 'bold'),
        legend.text=  element_text(size=20),
        axis.line = element_line(colour = "black"))+
  scale_fill_grey("Period") +
  theme_classic(base_size = 20, base_family = "") + 
  theme(panel.grid.minor = element_line(colour="grey", size=0.5)) +
  theme(axis.text.x = element_text(angle = 45, hjust = 1))

Answer 1

这是答案

#Plot absolute values
p1 <- ggplot(C_Em_df[C_Em_df$Type=="Sum",], aes(x = Driver, y = Value, fill = Period, width = .85)) +
  geom_bar(position = "dodge", stat = "identity") +
  labs(x = "", y = "Carbon emission (T/Year)") +
  theme(axis.text = element_text(size = 16),
        axis.title = element_text(size = 20), 
        legend.title = element_text(size = 20, face = 'bold'),
        legend.text=  element_text(size=20),
        axis.line = element_line(colour = "black"))+
  scale_fill_grey("Period") +
  theme_classic(base_size = 20, base_family = "") + 
  theme(panel.grid.minor = element_line(colour="grey", size=0.5)) +
  theme(axis.text.x = element_text(angle = 45, hjust = 1))

#add the number of observations
foo <- ggplot_build(p1)$data[[1]]
p2<-p1 + annotate("text", x = foo$x, y = foo$y + 50000, label = C_Em_df[C_Em_df$Type=="Sum",]$n, size = 4.5) 

#Plot Percentage values
p3 <- ggplot(C_Em_df[C_Em_df$Type=="Percentage",], aes(x = Driver, y = Value, fill = Period, width = .85)) +
  geom_bar(position = "dodge", stat = "identity") +
  scale_y_continuous(labels = percent_format(), limits=c(0,1))+
  labs(x = "", y = "Carbon Emissions (%)") +
  theme(axis.text = element_text(size = 16),
        axis.title = element_text(size = 20), 
        legend.title = element_text(size = 20, face = 'bold'),
        legend.text=  element_text(size=20),
        axis.line = element_line(colour = "black"))+
  scale_fill_grey("Period") +
  theme_classic(base_size = 20, base_family = "") + 
  theme(panel.grid.minor = element_line(colour="grey", size=0.5)) +
  theme(axis.text.x = element_text(angle = 45, hjust = 1))

# Plot two graphs together
install.packages("gridExtra")
library(gridExtra)
gA <- ggplotGrob(p2)
gB <- ggplotGrob(p3)
maxWidth = grid::unit.pmax(gA$widths[2:5], gB$widths[2:5])
gA$widths[2:5] <- as.list(maxWidth)
gB$widths[2:5] <- as.list(maxWidth)

p4 <- arrangeGrob(
  gA, gB, nrow = 2, heights = c(0.80, 0.80))