ggplot2，拼凑而成-轴标题的一部分被相邻图的边距阻塞

Question

我有两个折线图，使用“拼凑而成”在一个折线图的下方堆叠。我想要一个通用的y轴标题，所以我在两个折线图的上方添加了y轴标签。堆叠后，我发现y轴标签的下部被下部线条的边距阻塞了图表（如下面附图中的绿色和黄色绘图背景所示）。此处是代码和结果

# data
x<- 1:256
x
y<- runif(256, 0, 10)
y

data <- data.frame(x,y)
head(data)

# lc1
# Geom properties
lc1<- ggplot(data, aes(x=x, y=y)) + 
  geom_line()

# Scale
lc1<- lc1 +
  expand_limits(x = 0, y = 0) +
  scale_x_continuous(
    expand = c(0, 0),
    breaks = c(0, 32, 64, 96, 128, 160, 192, 224, 256),
    label = NULL
  ) +
  scale_y_continuous(expand = c(0, 0),
                     breaks = c(0, 5, 10))

# Aspect ratio
lc1 <- lc1 + theme(aspect.ratio = 0.15)

# Panel properties
lc1 <- lc1 +
  theme(panel.background = element_blank()) +
  theme(
    panel.grid.minor = element_blank(),
    panel.grid.major = element_blank(),
    legend.position = "none"
  )

# Axes lines, ticks, axis text
lc1 <- lc1 +
  theme(
    axis.line.x = element_line (colour = "grey", size = 0.5),
    axis.line.y = element_line(colour = "black", size = 0.5),
    axis.ticks.x = element_blank(),
    axis.ticks.y = element_line(colour = "black", size = 0.5),
    axis.ticks.length = unit(.15, "cm")
  ) +
  theme(
    axis.text.y = element_text(
      color = "black",
      face = "plain",
      size = 6,
      margin = margin(
        t = 0,
        r = 2,
        b = 0,
        l = 0
      ),
      angle = 0,
      vjust = 0,
      hjust = 0
    )
  )

# Title, caption, axes labels 
lc1<- lc1 + 
  ylab(label = "Y-axis label (unit)") +
  theme(axis.title.x = element_text(
    color = "black",
    size = 10,
    face = "bold",
    hjust = 0
  ))

# Plot margins
lc1 <- lc1 +
  theme(plot.margin = unit(c(-0.55,0,-0.53,0), "cm"))

# plot background
lc1<- lc1 + theme(plot.background = element_rect(fill = "green"))

lc1




# lc2
# Geom properties
lc2<- ggplot(data, aes(x=x, y=y)) + 
  geom_line()

# Scale
lc2<- lc2 +
  expand_limits(x = 0, y = 0) +
  scale_x_continuous(
    expand = c(0, 0),
    breaks = c(0, 32, 64, 96, 128, 160, 192, 224, 256),
    label = NULL
  ) +
  scale_y_continuous(expand = c(0, 0),
                     breaks = c(0, 5, 10))

# Aspect ratio
lc2 <- lc2 + theme(aspect.ratio = 0.15)

# Panel properties
lc2 <- lc2 +
  theme(panel.background = element_blank()) +
  theme(
    panel.grid.minor = element_blank(),
    panel.grid.major = element_blank(),
    legend.position = "none"
  )

# Axes lines, ticks, axis text
lc2 <- lc2 +
  theme(
    axis.line.x = element_line (colour = "grey", size = 0.5),
    axis.line.y = element_line(colour = "black", size = 0.5),
    axis.ticks.x = element_blank(),
    axis.ticks.y = element_line(colour = "black", size = 0.5),
    axis.ticks.length = unit(.15, "cm")
  ) +
  theme(
    axis.text.y = element_text(
      color = "black",
      face = "plain",
      size = 6,
      margin = margin(
        t = 0,
        r = 2,
        b = 0,
        l = 0
      ),
      angle = 0,
      vjust = 0,
      hjust = 0
    )
  )

# Title, caption, axes labels 
lc2<- lc2 + 
  ylab(label = "") +
  theme(axis.title.x = element_text(
    color = "black",
    size = 10,
    face = "bold",
    hjust = 0.5
  ))

# Plot margins
lc2 <- lc2 +
  theme(plot.margin = unit(c(-0.55,0,-0.53,0), "cm"))

# plot background
lc2<- lc2 + theme(plot.background = element_rect(fill = "yellow"))

lc2

# stacking
library(patchwork)

p<- (lc1/lc2)
p

因此，我尝试通过将下部图表的左边界从0减小到-1来解决问题，但是它没有改变边界，并且轴标题仍然被阻止。如果两个图表的左边距都减小为-1，y轴标题，则刻度不再可见，如下图所示。绿色和黄色填充矩形是绘图背景。

有人可以帮忙找到解决方法吗？有什么想法，我还能尝试什么？谢谢！

Answer 1

您可以只为组合图设置标题（而不能为lc1或lc2设置标题）。您需要为lc1和lc2设置空白的y标签，就像您已经为lc2设置的一样（例如ylab(label = "")。

p <- (lc1/lc2) + ylab(label = "Y-axis label (unit)")