如何在具有多个轴的Plotly (R)子图中正确放置轴标签？

library(plotly)

# 创建子图1
trace1 <- list(
  x = c(1, 2, 3),
  y = c(4, 5, 6),
  type = "scatter",
  mode = "lines",
  name = "Subplot 1"
)

# 创建子图2
trace2 <- list(
  x = c(1, 2, 3),
  y = c(7, 8, 9),
  type = "scatter",
  mode = "lines",
  name = "Subplot 2",
  xaxis = "x2",
  yaxis = "y2"
)

# 创建子图3
trace3 <- list(
  x = c(1, 2, 3),
  y = c(10, 11, 12),
  type = "scatter",
  mode = "lines",
  name = "Subplot 3",
  xaxis = "x3",
  yaxis = "y3"
)

# 创建子图4
trace4 <- list(
  x = c(1, 2, 3),
  y = c(13, 14, 15),
  type = "scatter",
  mode = "lines",
  name = "Subplot 4",
  xaxis = "x4",
  yaxis = "y4"
)

# 创建子图布局
layout <- list(
  xaxis = list(domain = c(0, 0.45)),
  xaxis2 = list(domain = c(0.55, 1)),
  xaxis3 = list(domain = c(0, 0.45), anchor = "y3"),
  xaxis4 = list(domain = c(0.55, 1), anchor = "y4"),
  yaxis = list(domain = c(0.55, 1)),
  yaxis2 = list(domain = c(0.55, 1), anchor = "x2"),
  yaxis3 = list(domain = c(0, 0.45)),
  yaxis4 = list(domain = c(0, 0.45), anchor = "x4"),
  showlegend = FALSE
)

# 创建子图
subplot <- subplot(
  list(trace1, trace2, trace3, trace4),
  layout = layout
)

# 设置轴标签位置和文本
subplot <- layout(
  subplot,
  xaxis = list(domain = c(0, 0.45), title = "X1 Axis"),
  xaxis2 = list(domain = c(0.55, 1), title = "X2 Axis"),
  xaxis3 = list(domain = c(0, 0.45), anchor = "y3", title = "X3 Axis"),
  xaxis4 = list(domain = c(0.55, 1), anchor = "y4", title = "X4 Axis"),
  yaxis = list(domain = c(0.55, 1), title = "Y1 Axis"),
  yaxis2 = list(domain = c(0.55, 1), anchor = "x2", title = "Y2 Axis"),
  yaxis3 = list(domain = c(0, 0.45), title = "Y3 Axis"),
  yaxis4 = list(domain = c(0, 0.45), anchor = "x4", title = "Y4 Axis")
)

# 显示子图
subplot