I have a viewport with two graphs drawn in a left to right fashion. I'm trying to have a single title appear over both of the graphs centered in the viewport. Is this possible? Sorry, no pic because of my noob status and I can't post the code because of my work environment.
I think you might be interested in the gridExtra package, which provides the grid.arrange() function that fulfills everything you wonder about.
With #Kevin's example, the command would be
grid.arrange(plots[[1]], plots[[2]], ncol=2,
main="test main", sub="subtitle test")
I have been using an almost unmodified version of code in this post to the ggplot2 mailing list to put a main title and subtitle above and below a matrix of plots. Credit to Baptiste Auguié.
arrange <- function(..., nrow=NULL, ncol=NULL, as.table=FALSE,
main=NULL, sub=NULL, plot=TRUE) {
dots <- list(...)
n <- length(dots)
if(is.null(nrow) & is.null(ncol)) { nrow = floor(n/2) ; ncol = ceiling(n/nrow)}
if(is.null(nrow)) { nrow = ceiling(n/ncol)}
if(is.null(ncol)) { ncol = ceiling(n/nrow)}
fg <- frameGrob(layout=grid.layout(nrow,ncol))
ii.p <- 1
for(ii.row in seq(1, nrow)){
ii.table.row <- ii.row
if(as.table) {ii.table.row <- nrow - ii.table.row + 1}
for(ii.col in seq(1, ncol)){
ii.table <- ii.p
if(ii.p > n) break
fg <- placeGrob(fg, ggplotGrob(dots[[ii.table]]),
row=ii.table.row, col=ii.col)
ii.p <- ii.p + 1
}
}
if(!is.null(main) | !is.null(sub)){
g <- frameGrob() # large frame to place title(s) and content
g <- packGrob(g, fg)
if (!is.null(main))
g <- packGrob(g, textGrob(main), side="top")
if (!is.null(sub))
g <- packGrob(g, textGrob(sub), side="bottom")
} else {
g <- fg
}
if(plot) grid.draw(g)
invisible(g)
}
library(ggplot2)
plots <- llply(1:2, function(.x) qplot(1:10,rnorm(10), main=paste("plot",.x)))
arrange(plots[[1]],plots[[2]], nrow=1, ncol = 2, as.table=TRUE, main="test main",
sub="subtitle test")
Produces:
Another Possibility, it's kind of cheating by way of creating a blank plot...
p1 <- ggplot(diamonds, aes(price,depth)) + geom_point()
p2 <- ggplot(diamonds, aes(price,carat)) + geom_point()
p3 <- ggplot(diamonds, aes(x=1,y=1,label="Title")) + geom_text(size=20) + opts(panel.background=theme_blank(), panel.grid.minor=theme_blank(), panel.grid.major=theme_blank(), axis.text.x=theme_blank(), axis.text.y=theme_blank(), axis.ticks=theme_blank(), axis.title.x=theme_blank(), axis.title.y=theme_blank())
vplayout <- function(x, y) viewport(layout.pos.row=x, layout.pos.col=y)
grid.newpage()
pushViewport(viewport(layout=grid.layout(4,4)))
print(p1,vp=vplayout(2:4,1:2))
print(p2,vp=vplayout(2:4,3:4))
print(p3,vp=vplayout(1,1:4))
Related
Is there a way to interactively and sequentially add more ggplots onto a plotting window, similar to how in base you can add more plots by using par(mfrow = ...). E.g. (for loop to simulate sequentially entering plot commands):
par(mfrow = c(4, 1))
for (i in 1:4) {
plot(tmp_df$x, tmp_df$y)
}
produces, sequentially, the first to the last row of the following plot:
Whereas, doing the same with ggplot just prints one plot to the plot window:
par(mfrow = c(4, 1))
for (i in 1:4) {
plot(ggplot(tmp_df, aes(x, y)) +
geom_point())
}
I already know how to use gridExtra::grid.arrange to arrange a list of ggplots, e.g.:
tmp_list <- list()
for (i in 1:4) {
tmp_list[[length(tmp_list) + 1]] <-
ggplot(tmp_df, aes(x, y)) +
geom_point()
}
gridExtra::grid.arrange(grobs = tmp_list, nrow = 4)
You can certainly add one plot at a time e.g by making a grid layout and drawing in specific viewports sequentially,
library(grid)
library(ggplot2)
gl <- replicate(4, ggplot(), F)
par <- function(mfrow = c(2,2)) pushViewport(viewport(layout = grid.layout(mfrow[1], mfrow[2])))
print.gg <- function(x) {
rc <- which(matrix(1:4, 2, 2) == ii, arr.ind = TRUE)
ggplot2:::print.ggplot(x, vp=viewport(layout.pos.row = rc[1,1], layout.pos.col = rc[1,2]))
ii <<- (ii+1)%%4
}
grid.newpage()
par()
for(ii in seq_along(gl))
print(gl[[ii]])
Here's a version with a gtable layout keeping track of occupied cells,
library(grid)
library(ggplot2)
library(gtable)
par <- function(mfrow=c(2,2)) {
nr <- mfrow[1]; nc <- mfrow[2]
.g_layout <<- gtable(widths = unit(rep(1/nc, nc), "npc"), heights = unit(rep(1/nr, nr), "npc"))
}
print.gg <- function(x) {
ntot <- prod(dim(.g_layout))
ii <- (length(.g_layout) + 1) %% (ntot+1)
rc <- which(matrix(seq_len(ntot), nrow = nrow(.g_layout), ncol = ncol(.g_layout)) == ii, arr.ind = TRUE)
.g_layout <<- gtable::gtable_add_grob(.g_layout, ggplotGrob(x), t = rc[1,1], l = rc[1,2])
grid.newpage()
grid.draw(.g_layout)
}
gl <- replicate(4, ggplot(), F)
par()
for(ii in seq_along(gl))
print(gl[[ii]])
I am trying to combine grid_arrange_shared_legend() and facet_wrap_labeller() in R. More specifically, I want to draw a figure including two ggplot figures with multiple panels each and have a common legend. I further want to italicize part of the facet strip labels. The former is possible with the grid_arrange_shared_legend() function introduced here, and the latter can be achieved with the facet_wrap_labeller() function here. However, I have not been successful in combining the two.
Here's an example.
library("ggplot2")
set.seed(1)
d <- data.frame(
f1 = rep(LETTERS[1:3], each = 100),
f2 = rep(letters[1:3], 100),
v1 = runif(3 * 100),
v2 = rnorm(3 * 100)
)
p1 <- ggplot(d, aes(v1, v2, color = f2)) + geom_point() + facet_wrap(~f1)
p2 <- ggplot(d, aes(v1, v2, color = f2)) + geom_smooth() + facet_wrap(~f1)
I can place p1 and p2 in the same figure and have a common legend using grid_arrange_shared_legend() (slightly modified from the original).
grid_arrange_shared_legend <- function(...) {
plots <- list(...)
g <- ggplotGrob(plots[[1]] + theme(legend.position = "right"))$grobs
legend <- g[[which(sapply(g, function(x) x$name) == "guide-box")]]
lheight <- sum(legend$width)
grid.arrange(
do.call(arrangeGrob, lapply(plots, function(x)
x + theme(legend.position = "none"))),
legend,
ncol = 2,
widths = unit.c(unit(1, "npc") - lheight, lheight))
}
grid_arrange_shared_legend(p1, p2)
Here's what I get.
It is possible to italicize part of the strip label by facet_wrap_labeller().
facet_wrap_labeller <- function(gg.plot,labels=NULL) {
require(gridExtra)
g <- ggplotGrob(gg.plot)
gg <- g$grobs
strips <- grep("strip_t", names(gg))
for(ii in seq_along(labels)) {
modgrob <- getGrob(gg[[strips[ii]]], "strip.text",
grep=TRUE, global=TRUE)
gg[[strips[ii]]]$children[[modgrob$name]] <- editGrob(modgrob,label=labels[ii])
}
g$grobs <- gg
class(g) = c("arrange", "ggplot",class(g))
g
}
facet_wrap_labeller(p1,
labels = c(
expression(paste("A ", italic(italic))),
expression(paste("B ", italic(italic))),
expression(paste("C ", italic(italic)))
)
)
However, I cannot combine the two in a straightforward manner.
p3 <- facet_wrap_labeller(p1,
labels = c(
expression(paste("A ", italic(italic))),
expression(paste("B ", italic(italic))),
expression(paste("C ", italic(italic)))
)
)
p4 <- facet_wrap_labeller(p2,
labels = c(
expression(paste("A ", italic(italic))),
expression(paste("B ", italic(italic))),
expression(paste("C ", italic(italic)))
)
)
grid_arrange_shared_legend(p3, p4)
# Error in plot_clone(p) : attempt to apply non-function
Does anyone know how to modify either or both of the functions so that they can be combined? Or is there any other way to achieve the goal?
You need to pass the gtable instead of the ggplot,
library(gtable)
library("ggplot2")
library(grid)
set.seed(1)
d <- data.frame(
f1 = rep(LETTERS[1:3], each = 100),
f2 = rep(letters[1:3], 100),
v1 = runif(3 * 100),
v2 = rnorm(3 * 100)
)
p1 <- ggplot(d, aes(v1, v2, color = f2)) + geom_point() + facet_wrap(~f1)
p2 <- ggplot(d, aes(v1, v2, color = f2)) + geom_smooth() + facet_wrap(~f1)
facet_wrap_labeller <- function(g, labels=NULL) {
gg <- g$grobs
strips <- grep("strip_t", names(gg))
for(ii in seq_along(labels)) {
oldgrob <- getGrob(gg[[strips[ii]]], "strip.text",
grep=TRUE, global=TRUE)
newgrob <- editGrob(oldgrob,label=labels[ii])
gg[[strips[ii]]]$children[[oldgrob$name]] <- newgrob
}
g$grobs <- gg
g
}
combined_fun <- function(p1, p2, labs1) {
g1 <- ggplotGrob(p1 + theme(legend.position = "right"))
g2 <- ggplotGrob(p2 + theme(legend.position = "none"))
g1 <- facet_wrap_labeller(g1, labs1)
legend <- gtable_filter(g1, "guide-box", trim = TRUE)
g1p <- g1[,-(ncol(g1)-1)]
lw <- sum(legend$width)
g12 <- rbind(g1p, g2, size="first")
g12$widths <- unit.pmax(g1p$widths, g2$widths)
g12 <- gtable_add_cols(g12, widths = lw)
g12 <- gtable_add_grob(g12, legend,
t = 1, l = ncol(g12), b = nrow(g12))
g12
}
test <- combined_fun(p1, p2, labs1 = c(
expression(paste("A ", italic(italic))),
expression(paste("B ", italic(italic))),
expression(paste("C ", italic(italic)))
)
)
grid.draw(test)
I have the same problem as this user - I have a 'jagged' faceted plot, in which the bottom row has fewer panels than the other rows, and I would like to have x-axis ticks on the bottom of each column.
The suggested solution for that problem was to set scales="free_x". (In ggplot 0.9.2.1; I believe the behavior I'm looking for was default in earlier versions.) That's a poor solution in my case: my actual axis labels will be rather long, so putting them under each row will occupy too much room. The results are something like this:
x <- gl(3, 1, 15, labels=paste("this is a very long axis label ", letters[1:5]))
y <- rnorm(length(x))
l <- gl(5, 3, 15)
d <- data.frame(x=x, y=y, l=l)
ggplot(d, aes(x=x, y=y)) + geom_point() + facet_wrap(~l, scales="free_x") +
theme(axis.text.x=element_text(angle=90, hjust=1))
In a comment here, Andrie suggests that it can be done manually in grid but I have no idea how to get started on that.
If I remember right, there were questions on both how to add all labels to the same line under the last column and how to lift these last labels up to the next row. So here is the function for both cases:
Edit: since this is like a substitute for print.ggplot (see getAnywhere(print.ggplot)) I have added some lines from it to preserve functionality.
Edit 2: I have improved it a bit more: no need to specify nrow and ncol anymore, plots with all the panels can be printed too.
library(grid)
# pos - where to add new labels
# newpage, vp - see ?print.ggplot
facetAdjust <- function(x, pos = c("up", "down"),
newpage = is.null(vp), vp = NULL)
{
# part of print.ggplot
ggplot2:::set_last_plot(x)
if(newpage)
grid.newpage()
pos <- match.arg(pos)
p <- ggplot_build(x)
gtable <- ggplot_gtable(p)
# finding dimensions
dims <- apply(p$panel$layout[2:3], 2, max)
nrow <- dims[1]
ncol <- dims[2]
# number of panels in the plot
panels <- sum(grepl("panel", names(gtable$grobs)))
space <- ncol * nrow
# missing panels
n <- space - panels
# checking whether modifications are needed
if(panels != space){
# indices of panels to fix
idx <- (space - ncol - n + 1):(space - ncol)
# copying x-axis of the last existing panel to the chosen panels
# in the row above
gtable$grobs[paste0("axis_b",idx)] <- list(gtable$grobs[[paste0("axis_b",panels)]])
if(pos == "down"){
# if pos == down then shifting labels down to the same level as
# the x-axis of last panel
rows <- grep(paste0("axis_b\\-[", idx[1], "-", idx[n], "]"),
gtable$layout$name)
lastAxis <- grep(paste0("axis_b\\-", panels), gtable$layout$name)
gtable$layout[rows, c("t","b")] <- gtable$layout[lastAxis, c("t")]
}
}
# again part of print.ggplot, plotting adjusted version
if(is.null(vp)){
grid.draw(gtable)
}
else{
if (is.character(vp))
seekViewport(vp)
else pushViewport(vp)
grid.draw(gtable)
upViewport()
}
invisible(p)
}
And here is how it looks
d <- ggplot(diamonds, aes(carat, price, fill = ..density..)) +
xlim(0, 2) + stat_binhex(na.rm = TRUE) + theme(aspect.ratio = 1) +
facet_wrap(~ color)
facetAdjust(d)
facetAdjust(d, "down")
Edit 3:
This is an alternative solution, the one above is fine as well.
There are some issues when one wants to use ggsave together with facetAdjust. A plot of class of ggplot is required because of two parts in the source code of ggsave: print(plot) and default_name(plot) in case one does not provide a filename manually (according to ?ggsave it seems that it is not supposed to work, though). Hence, given a filename, there is a workaround (possibly with side effects in some cases):
First, let us consider the separate function that achieves the main effect of floating axis. Normally, it would return a gtable object, however we use class(gtable) <- c("facetAdjust", "gtable", "ggplot"). In this way, it is allowed to use ggsave and print(plot) works as required (see below for print.facetAdjust)
facetAdjust <- function(x, pos = c("up", "down"))
{
pos <- match.arg(pos)
p <- ggplot_build(x)
gtable <- ggplot_gtable(p); dev.off()
dims <- apply(p$panel$layout[2:3], 2, max)
nrow <- dims[1]
ncol <- dims[2]
panels <- sum(grepl("panel", names(gtable$grobs)))
space <- ncol * nrow
n <- space - panels
if(panels != space){
idx <- (space - ncol - n + 1):(space - ncol)
gtable$grobs[paste0("axis_b",idx)] <- list(gtable$grobs[[paste0("axis_b",panels)]])
if(pos == "down"){
rows <- grep(paste0("axis_b\\-[", idx[1], "-", idx[n], "]"),
gtable$layout$name)
lastAxis <- grep(paste0("axis_b\\-", panels), gtable$layout$name)
gtable$layout[rows, c("t","b")] <- gtable$layout[lastAxis, c("t")]
}
}
class(gtable) <- c("facetAdjust", "gtable", "ggplot"); gtable
}
The function for printing which differs only by few lines from ggplot2:::print.ggplot:
print.facetAdjust <- function(x, newpage = is.null(vp), vp = NULL) {
if(newpage)
grid.newpage()
if(is.null(vp)){
grid.draw(x)
} else {
if (is.character(vp))
seekViewport(vp)
else pushViewport(vp)
grid.draw(x)
upViewport()
}
invisible(x)
}
Example:
d <- ggplot(diamonds, aes(carat, price, fill = ..density..)) +
xlim(0, 2) + stat_binhex(na.rm = TRUE) + theme(aspect.ratio = 1) +
facet_wrap(~ color)
p <- facetAdjust(d) # No output
print(p) # The same output as with the old version of facetAdjust()
ggsave("name.pdf", p) # Works, a filename is necessary
I have the same problem as this user - I have a 'jagged' faceted plot, in which the bottom row has fewer panels than the other rows, and I would like to have x-axis ticks on the bottom of each column.
The suggested solution for that problem was to set scales="free_x". (In ggplot 0.9.2.1; I believe the behavior I'm looking for was default in earlier versions.) That's a poor solution in my case: my actual axis labels will be rather long, so putting them under each row will occupy too much room. The results are something like this:
x <- gl(3, 1, 15, labels=paste("this is a very long axis label ", letters[1:5]))
y <- rnorm(length(x))
l <- gl(5, 3, 15)
d <- data.frame(x=x, y=y, l=l)
ggplot(d, aes(x=x, y=y)) + geom_point() + facet_wrap(~l, scales="free_x") +
theme(axis.text.x=element_text(angle=90, hjust=1))
In a comment here, Andrie suggests that it can be done manually in grid but I have no idea how to get started on that.
If I remember right, there were questions on both how to add all labels to the same line under the last column and how to lift these last labels up to the next row. So here is the function for both cases:
Edit: since this is like a substitute for print.ggplot (see getAnywhere(print.ggplot)) I have added some lines from it to preserve functionality.
Edit 2: I have improved it a bit more: no need to specify nrow and ncol anymore, plots with all the panels can be printed too.
library(grid)
# pos - where to add new labels
# newpage, vp - see ?print.ggplot
facetAdjust <- function(x, pos = c("up", "down"),
newpage = is.null(vp), vp = NULL)
{
# part of print.ggplot
ggplot2:::set_last_plot(x)
if(newpage)
grid.newpage()
pos <- match.arg(pos)
p <- ggplot_build(x)
gtable <- ggplot_gtable(p)
# finding dimensions
dims <- apply(p$panel$layout[2:3], 2, max)
nrow <- dims[1]
ncol <- dims[2]
# number of panels in the plot
panels <- sum(grepl("panel", names(gtable$grobs)))
space <- ncol * nrow
# missing panels
n <- space - panels
# checking whether modifications are needed
if(panels != space){
# indices of panels to fix
idx <- (space - ncol - n + 1):(space - ncol)
# copying x-axis of the last existing panel to the chosen panels
# in the row above
gtable$grobs[paste0("axis_b",idx)] <- list(gtable$grobs[[paste0("axis_b",panels)]])
if(pos == "down"){
# if pos == down then shifting labels down to the same level as
# the x-axis of last panel
rows <- grep(paste0("axis_b\\-[", idx[1], "-", idx[n], "]"),
gtable$layout$name)
lastAxis <- grep(paste0("axis_b\\-", panels), gtable$layout$name)
gtable$layout[rows, c("t","b")] <- gtable$layout[lastAxis, c("t")]
}
}
# again part of print.ggplot, plotting adjusted version
if(is.null(vp)){
grid.draw(gtable)
}
else{
if (is.character(vp))
seekViewport(vp)
else pushViewport(vp)
grid.draw(gtable)
upViewport()
}
invisible(p)
}
And here is how it looks
d <- ggplot(diamonds, aes(carat, price, fill = ..density..)) +
xlim(0, 2) + stat_binhex(na.rm = TRUE) + theme(aspect.ratio = 1) +
facet_wrap(~ color)
facetAdjust(d)
facetAdjust(d, "down")
Edit 3:
This is an alternative solution, the one above is fine as well.
There are some issues when one wants to use ggsave together with facetAdjust. A plot of class of ggplot is required because of two parts in the source code of ggsave: print(plot) and default_name(plot) in case one does not provide a filename manually (according to ?ggsave it seems that it is not supposed to work, though). Hence, given a filename, there is a workaround (possibly with side effects in some cases):
First, let us consider the separate function that achieves the main effect of floating axis. Normally, it would return a gtable object, however we use class(gtable) <- c("facetAdjust", "gtable", "ggplot"). In this way, it is allowed to use ggsave and print(plot) works as required (see below for print.facetAdjust)
facetAdjust <- function(x, pos = c("up", "down"))
{
pos <- match.arg(pos)
p <- ggplot_build(x)
gtable <- ggplot_gtable(p); dev.off()
dims <- apply(p$panel$layout[2:3], 2, max)
nrow <- dims[1]
ncol <- dims[2]
panels <- sum(grepl("panel", names(gtable$grobs)))
space <- ncol * nrow
n <- space - panels
if(panels != space){
idx <- (space - ncol - n + 1):(space - ncol)
gtable$grobs[paste0("axis_b",idx)] <- list(gtable$grobs[[paste0("axis_b",panels)]])
if(pos == "down"){
rows <- grep(paste0("axis_b\\-[", idx[1], "-", idx[n], "]"),
gtable$layout$name)
lastAxis <- grep(paste0("axis_b\\-", panels), gtable$layout$name)
gtable$layout[rows, c("t","b")] <- gtable$layout[lastAxis, c("t")]
}
}
class(gtable) <- c("facetAdjust", "gtable", "ggplot"); gtable
}
The function for printing which differs only by few lines from ggplot2:::print.ggplot:
print.facetAdjust <- function(x, newpage = is.null(vp), vp = NULL) {
if(newpage)
grid.newpage()
if(is.null(vp)){
grid.draw(x)
} else {
if (is.character(vp))
seekViewport(vp)
else pushViewport(vp)
grid.draw(x)
upViewport()
}
invisible(x)
}
Example:
d <- ggplot(diamonds, aes(carat, price, fill = ..density..)) +
xlim(0, 2) + stat_binhex(na.rm = TRUE) + theme(aspect.ratio = 1) +
facet_wrap(~ color)
p <- facetAdjust(d) # No output
print(p) # The same output as with the old version of facetAdjust()
ggsave("name.pdf", p) # Works, a filename is necessary
I have the same problem as this user - I have a 'jagged' faceted plot, in which the bottom row has fewer panels than the other rows, and I would like to have x-axis ticks on the bottom of each column.
The suggested solution for that problem was to set scales="free_x". (In ggplot 0.9.2.1; I believe the behavior I'm looking for was default in earlier versions.) That's a poor solution in my case: my actual axis labels will be rather long, so putting them under each row will occupy too much room. The results are something like this:
x <- gl(3, 1, 15, labels=paste("this is a very long axis label ", letters[1:5]))
y <- rnorm(length(x))
l <- gl(5, 3, 15)
d <- data.frame(x=x, y=y, l=l)
ggplot(d, aes(x=x, y=y)) + geom_point() + facet_wrap(~l, scales="free_x") +
theme(axis.text.x=element_text(angle=90, hjust=1))
In a comment here, Andrie suggests that it can be done manually in grid but I have no idea how to get started on that.
If I remember right, there were questions on both how to add all labels to the same line under the last column and how to lift these last labels up to the next row. So here is the function for both cases:
Edit: since this is like a substitute for print.ggplot (see getAnywhere(print.ggplot)) I have added some lines from it to preserve functionality.
Edit 2: I have improved it a bit more: no need to specify nrow and ncol anymore, plots with all the panels can be printed too.
library(grid)
# pos - where to add new labels
# newpage, vp - see ?print.ggplot
facetAdjust <- function(x, pos = c("up", "down"),
newpage = is.null(vp), vp = NULL)
{
# part of print.ggplot
ggplot2:::set_last_plot(x)
if(newpage)
grid.newpage()
pos <- match.arg(pos)
p <- ggplot_build(x)
gtable <- ggplot_gtable(p)
# finding dimensions
dims <- apply(p$panel$layout[2:3], 2, max)
nrow <- dims[1]
ncol <- dims[2]
# number of panels in the plot
panels <- sum(grepl("panel", names(gtable$grobs)))
space <- ncol * nrow
# missing panels
n <- space - panels
# checking whether modifications are needed
if(panels != space){
# indices of panels to fix
idx <- (space - ncol - n + 1):(space - ncol)
# copying x-axis of the last existing panel to the chosen panels
# in the row above
gtable$grobs[paste0("axis_b",idx)] <- list(gtable$grobs[[paste0("axis_b",panels)]])
if(pos == "down"){
# if pos == down then shifting labels down to the same level as
# the x-axis of last panel
rows <- grep(paste0("axis_b\\-[", idx[1], "-", idx[n], "]"),
gtable$layout$name)
lastAxis <- grep(paste0("axis_b\\-", panels), gtable$layout$name)
gtable$layout[rows, c("t","b")] <- gtable$layout[lastAxis, c("t")]
}
}
# again part of print.ggplot, plotting adjusted version
if(is.null(vp)){
grid.draw(gtable)
}
else{
if (is.character(vp))
seekViewport(vp)
else pushViewport(vp)
grid.draw(gtable)
upViewport()
}
invisible(p)
}
And here is how it looks
d <- ggplot(diamonds, aes(carat, price, fill = ..density..)) +
xlim(0, 2) + stat_binhex(na.rm = TRUE) + theme(aspect.ratio = 1) +
facet_wrap(~ color)
facetAdjust(d)
facetAdjust(d, "down")
Edit 3:
This is an alternative solution, the one above is fine as well.
There are some issues when one wants to use ggsave together with facetAdjust. A plot of class of ggplot is required because of two parts in the source code of ggsave: print(plot) and default_name(plot) in case one does not provide a filename manually (according to ?ggsave it seems that it is not supposed to work, though). Hence, given a filename, there is a workaround (possibly with side effects in some cases):
First, let us consider the separate function that achieves the main effect of floating axis. Normally, it would return a gtable object, however we use class(gtable) <- c("facetAdjust", "gtable", "ggplot"). In this way, it is allowed to use ggsave and print(plot) works as required (see below for print.facetAdjust)
facetAdjust <- function(x, pos = c("up", "down"))
{
pos <- match.arg(pos)
p <- ggplot_build(x)
gtable <- ggplot_gtable(p); dev.off()
dims <- apply(p$panel$layout[2:3], 2, max)
nrow <- dims[1]
ncol <- dims[2]
panels <- sum(grepl("panel", names(gtable$grobs)))
space <- ncol * nrow
n <- space - panels
if(panels != space){
idx <- (space - ncol - n + 1):(space - ncol)
gtable$grobs[paste0("axis_b",idx)] <- list(gtable$grobs[[paste0("axis_b",panels)]])
if(pos == "down"){
rows <- grep(paste0("axis_b\\-[", idx[1], "-", idx[n], "]"),
gtable$layout$name)
lastAxis <- grep(paste0("axis_b\\-", panels), gtable$layout$name)
gtable$layout[rows, c("t","b")] <- gtable$layout[lastAxis, c("t")]
}
}
class(gtable) <- c("facetAdjust", "gtable", "ggplot"); gtable
}
The function for printing which differs only by few lines from ggplot2:::print.ggplot:
print.facetAdjust <- function(x, newpage = is.null(vp), vp = NULL) {
if(newpage)
grid.newpage()
if(is.null(vp)){
grid.draw(x)
} else {
if (is.character(vp))
seekViewport(vp)
else pushViewport(vp)
grid.draw(x)
upViewport()
}
invisible(x)
}
Example:
d <- ggplot(diamonds, aes(carat, price, fill = ..density..)) +
xlim(0, 2) + stat_binhex(na.rm = TRUE) + theme(aspect.ratio = 1) +
facet_wrap(~ color)
p <- facetAdjust(d) # No output
print(p) # The same output as with the old version of facetAdjust()
ggsave("name.pdf", p) # Works, a filename is necessary