我一直在尝试扩展我的方案，从这里开始，以利用facets（特别是facet_grid()）。
我看到了这个例子，但是我似乎无法让它适用于我的geom_bar()和geom_point()组合。我尝试使用来自示例的代码，只是将其从facet_wrap更改为facet_grid，这似乎也使第一层未显示。
当涉及到网格和grobs时，我非常菜鸟，所以如果有人可以指导如何使P1显示在左y轴上，P2显示在右y轴上，那就太好了。
数据
library(ggplot2)
library(gtable)
library(grid)
library(data.table)
library(scales)
grid.newpage()
dt.diamonds <- as.data.table(diamonds)
d1 <- dt.diamonds[,list(revenue = sum(price),
stones = length(price)),
by=c("clarity","cut")]
setkey(d1, clarity,cut)
p1 & p2
p1 <- ggplot(d1, aes(x=clarity,y=revenue, fill=cut)) +
geom_bar(stat="identity") +
labs(x="clarity", y="revenue") +
facet_grid(. ~ cut) +
scale_y_continuous(labels=dollar, expand=c(0,0)) +
theme(axis.text.x = element_text(angle = 90, hjust = 1),
axis.text.y = element_text(colour="#4B92DB"),
legend.position="bottom")
p2 <- ggplot(d1, aes(x=clarity, y=stones, colour="red")) +
geom_point(size=6) +
labs(x="", y="number of stones") + expand_limits(y=0) +
scale_y_continuous(labels=comma, expand=c(0,0)) +
scale_colour_manual(name = '',values =c("red","green"), labels = c("Number of Stones"))+
facet_grid(. ~ cut) +
theme(axis.text.y = element_text(colour = "red")) +
theme(panel.background = element_rect(fill = NA),
panel.grid.major = element_blank(),
panel.grid.minor = element_blank(),
panel.border = element_rect(fill=NA,colour="grey50"),
legend.position="bottom")
尝试结合（基于上面链接的示例） 这在第一个for循环中失败，我怀疑是由于硬编码的geom_point.points，但我不知道如何使其适合我的图表（或足够流畅以适应各种图表）
# extract gtable
g1 <- ggplot_gtable(ggplot_build(p1))
g2 <- ggplot_gtable(ggplot_build(p2))
combo_grob <- g2
pos <- length(combo_grob) - 1
combo_grob$grobs[[pos]] <- cbind(g1$grobs[[pos]],
g2$grobs[[pos]], size = 'first')
panel_num <- length(unique(d1$cut))
for (i in seq(panel_num))
{
grid.ls(g1$grobs[[i + 1]])
panel_grob <- getGrob(g1$grobs[[i + 1]], 'geom_point.points',
grep = TRUE, global = TRUE)
combo_grob$grobs[[i + 1]] <- addGrob(combo_grob$grobs[[i + 1]],
panel_grob)
}
pos_a <- grep('axis_l', names(g1$grobs))
axis <- g1$grobs[pos_a]
for (i in seq(along = axis))
{
if (i %in% c(2, 4))
{
pp <- c(subset(g1$layout, name == paste0('panel-', i), se = t:r))
ax <- axis[[1]]$children[[2]]
ax$widths <- rev(ax$widths)
ax$grobs <- rev(ax$grobs)
ax$grobs[[1]]$x <- ax$grobs[[1]]$x - unit(1, "npc") + unit(0.5, "cm")
ax$grobs[[2]]$x <- ax$grobs[[2]]$x - unit(1, "npc") + unit(0.8, "cm")
combo_grob <- gtable_add_cols(combo_grob, g2$widths[g2$layout[pos_a[i],]$l], length(combo_grob$widths) - 1)
combo_grob <- gtable_add_grob(combo_grob, ax, pp$t, length(combo_grob$widths) - 1, pp$b)
}
}
pp <- c(subset(g1$layout, name == 'ylab', se = t:r))
ia <- which(g1$layout$name == "ylab")
ga <- g1$grobs[[ia]]
ga$rot <- 270
ga$x <- ga$x - unit(1, "npc") + unit(1.5, "cm")
combo_grob <- gtable_add_cols(combo_grob, g2$widths[g2$layout[ia,]$l], length(combo_grob$widths) - 1)
combo_grob <- gtable_add_grob(combo_grob, ga, pp$t, length(combo_grob$widths) - 1, pp$b)
combo_grob$layout$clip <- "off"
grid.draw(combo_grob)
修改以尝试适用于facet_wrap
以下代码仍适用于使用ggplot2 2.0.0的facet_grid
g1 <- ggplot_gtable(ggplot_build(p1))
g2 <- ggplot_gtable(ggplot_build(p2))
pp <- c(subset(g1$layout, name == "panel", se = t:r))
g <- gtable_add_grob(g1, g2$grobs[which(g2$layout$name == "panel")], pp$t,
pp$l, pp$b, pp$l)
# axis tweaks
ia <- which(g2$layout$name == "axis-l")
ga <- g2$grobs[[ia]]
ax <- ga$children[[2]]
ax$widths <- rev(ax$widths)
ax$grobs <- rev(ax$grobs)
ax$grobs[[1]]$x <- ax$grobs[[1]]$x - unit(1, "npc") + unit(0.15, "cm")
g <- gtable_add_cols(g, g2$widths[g2$layout[ia, ]$l], length(g$widths) - 1)
g <- gtable_add_grob(g, ax, unique(pp$t), length(g$widths) - 1)
# Add second y-axis title
ia <- which(g2$layout$name == "ylab")
ax <- g2$grobs[[ia]]
# str(ax) # you can change features (size, colour etc for these -
# change rotation below
ax$rot <- 90
g <- gtable_add_cols(g, g2$widths[g2$layout[ia, ]$l], length(g$widths) - 1)
g <- gtable_add_grob(g, ax, unique(pp$t), length(g$widths) - 1)
# Add legend to the code
leg1 <- g1$grobs[[which(g1$layout$name == "guide-box")]]
leg2 <- g2$grobs[[which(g2$layout$name == "guide-box")]]
g$grobs[[which(g$layout$name == "guide-box")]] <-
gtable:::cbind_gtable(leg1, leg2, "first")
grid.draw(g)
g <- gtable_add_grob(g1, g2$grobs[which(g2$layout$name == "panel")], pp$t, pp$l, pp$b, pp$l)，然后继续之前的步骤直到倒数第二行 - 将其改为g <- gtable_add_grob(g, ax, unique(pp$t), length(g$widths) - 1)。 - user20650