我不确定您是否仍在寻找解决方案，但这是相当普遍的。我正在使用 ggplot 2.1.0（现在在 CRAN 上）。它基于此解决方案。我把问题分成两部分。首先，我处理图的左侧，确保轴材料的宽度相同。其他人已经这样做了，并且在SO上有解决方案。但我不认为结果看起来很好。我希望面板也可以在右侧对齐。其次，该过程确保面板右侧的列的宽度相同。它通过在每个图的右侧添加适当宽度的列来做到这一点。（可能有更简洁的方法。有 - 请参阅@baptiste 解决方案。）
library(grid) # for pmax
library(gridExtra) # to arrange the plots
library(ggplot2) # to construct the plots
library(gtable) # to add columns to gtables of plots without legends
mpg$g = "Strip text"
# Four fairly irregular plots: legends, faceting, strips
p1 <- ggplot(mpg, aes(displ, 1000*cty)) +
geom_point() +
facet_grid(. ~ drv) +
stat_smooth(method = "lm")
p2 <- ggplot(mpg, aes(x = hwy, y = cyl, colour = factor(cyl))) +
geom_point() +
theme(legend.position=c(.8,.6),
legend.key.size = unit(.3, "cm"))
p3 <- ggplot(mpg, aes(displ, cty, colour = factor(drv))) +
geom_point() +
facet_grid(. ~ drv)
p4 <- ggplot(mpg, aes(displ, cty, colour = factor(drv))) +
geom_point() +
facet_grid(g ~ .)
# Sometimes easier to work with lists, and it generalises nicely
plots = list(p1, p2, p3, p4)
# Convert to gtables
g = lapply(plots, ggplotGrob)
# Apply the un-exported unit.list function for grid package to each plot
g.widths = lapply(g, function(x) grid:::unit.list(x$widths))
## Part 1: Make sure the widths of left axis materials are the same across the plots
# Get first three widths from each plot
g3.widths <- lapply(g.widths, function(x) x[1:3])
# Get maximum widths for first three widths across the plots
g3max.widths <- do.call(unit.pmax, g3.widths)
# Apply the maximum widths to each plot
for(i in 1:length(plots)) g[[i]]$widths[1:3] = g3max.widths
# Draw it
do.call(grid.arrange, c(g, ncol = 1))
## Part 2: Get the right side of the panels aligned
# Locate the panels
panels <- lapply(g, function(x) x$layout[grepl("panel", x$layout$name), ])
# Get the position of right most panel
r.panel = lapply(panels, function(x) max(x$r)) # position of right most panel
# Get the number of columns to the right of the panels
n.cols = lapply(g.widths, function(x) length(x)) # right most column
# Get the widths of these columns to the right of the panels
r.widths <- mapply(function(x,y,z) x[(y+1):z], g.widths, r.panel, n.cols)
# Get the sum of these widths
sum.r.widths <- lapply(r.widths, sum)
# Get the maximum of these widths
r.width = do.call(unit.pmax, sum.r.widths)
# Add a column to the right of each gtable of width
# equal to the difference between the maximum
# and the width of each gtable's columns to the right of the panel.
for(i in 1:length(plots)) g[[i]] = gtable_add_cols(g[[i]], r.width - sum.r.widths[[i]], -1)
# Draw it
do.call(grid.arrange, c(g, ncol = 1))
