Related
I've got a few different categories that I want to plot. These are different categories, each with their own set of labels, but which makes sense to group together in the document. The following gives some simple stacked bar chart examples:
df <- data.frame(x=c("a", "b", "c"),
y=c("happy", "sad", "ambivalent about life"))
ggplot(df, aes(x=factor(0), fill=x)) + geom_bar()
ggplot(df, aes(x=factor(0), fill=y)) + geom_bar()
The problem is that with different labels, the legends have different widths, which means the plots have different widths, leading to things looking a bit goofy if I make a table or \subfigure elements. How can I fix this?
Is there a way to explicitly set the width (absolute or relative) of either the plot or the legend?
Edit: Very easy with egg package
# install.packages("egg")
library(egg)
p1 <- ggplot(data.frame(x=c("a","b","c"),
y=c("happy","sad","ambivalent about life")),
aes(x=factor(0),fill=x)) +
geom_bar()
p2 <- ggplot(data.frame(x=c("a","b","c"),
y=c("happy","sad","ambivalent about life")),
aes(x=factor(0),fill=y)) +
geom_bar()
ggarrange(p1,p2, ncol = 1)
Original Udated to ggplot2 2.2.1
Here's a solution that uses functions from the gtable package, and focuses on the widths of the legend boxes. (A more general solution can be found here.)
library(ggplot2)
library(gtable)
library(grid)
library(gridExtra)
# Your plots
p1 <- ggplot(data.frame(x=c("a","b","c"),y=c("happy","sad","ambivalent about life")),aes(x=factor(0),fill=x)) + geom_bar()
p2 <- ggplot(data.frame(x=c("a","b","c"),y=c("happy","sad","ambivalent about life")),aes(x=factor(0),fill=y)) + geom_bar()
# Get the gtables
gA <- ggplotGrob(p1)
gB <- ggplotGrob(p2)
# Set the widths
gA$widths <- gB$widths
# Arrange the two charts.
# The legend boxes are centered
grid.newpage()
grid.arrange(gA, gB, nrow = 2)
If in addition, the legend boxes need to be left justified, and borrowing some code from here written by #Julius
p1 <- ggplot(data.frame(x=c("a","b","c"),y=c("happy","sad","ambivalent about life")),aes(x=factor(0),fill=x)) + geom_bar()
p2 <- ggplot(data.frame(x=c("a","b","c"),y=c("happy","sad","ambivalent about life")),aes(x=factor(0),fill=y)) + geom_bar()
# Get the widths
gA <- ggplotGrob(p1)
gB <- ggplotGrob(p2)
# The parts that differs in width
leg1 <- convertX(sum(with(gA$grobs[[15]], grobs[[1]]$widths)), "mm")
leg2 <- convertX(sum(with(gB$grobs[[15]], grobs[[1]]$widths)), "mm")
# Set the widths
gA$widths <- gB$widths
# Add an empty column of "abs(diff(widths)) mm" width on the right of
# legend box for gA (the smaller legend box)
gA$grobs[[15]] <- gtable_add_cols(gA$grobs[[15]], unit(abs(diff(c(leg1, leg2))), "mm"))
# Arrange the two charts
grid.newpage()
grid.arrange(gA, gB, nrow = 2)
Alternative solutions There are rbind and cbind functions in the gtable package for combining grobs into one grob. For the charts here, the widths should be set using size = "max", but the CRAN version of gtable throws an error.
One option: It should be obvious that the legend in the second plot is wider. Therefore, use the size = "last" option.
# Get the grobs
gA <- ggplotGrob(p1)
gB <- ggplotGrob(p2)
# Combine the plots
g = rbind(gA, gB, size = "last")
# Draw it
grid.newpage()
grid.draw(g)
Left-aligned legends:
# Get the grobs
gA <- ggplotGrob(p1)
gB <- ggplotGrob(p2)
# The parts that differs in width
leg1 <- convertX(sum(with(gA$grobs[[15]], grobs[[1]]$widths)), "mm")
leg2 <- convertX(sum(with(gB$grobs[[15]], grobs[[1]]$widths)), "mm")
# Add an empty column of "abs(diff(widths)) mm" width on the right of
# legend box for gA (the smaller legend box)
gA$grobs[[15]] <- gtable_add_cols(gA$grobs[[15]], unit(abs(diff(c(leg1, leg2))), "mm"))
# Combine the plots
g = rbind(gA, gB, size = "last")
# Draw it
grid.newpage()
grid.draw(g)
A second option is to use rbind from Baptiste's gridExtra package
# Get the grobs
gA <- ggplotGrob(p1)
gB <- ggplotGrob(p2)
# Combine the plots
g = gridExtra::rbind.gtable(gA, gB, size = "max")
# Draw it
grid.newpage()
grid.draw(g)
Left-aligned legends:
# Get the grobs
gA <- ggplotGrob(p1)
gB <- ggplotGrob(p2)
# The parts that differs in width
leg1 <- convertX(sum(with(gA$grobs[[15]], grobs[[1]]$widths)), "mm")
leg2 <- convertX(sum(with(gB$grobs[[15]], grobs[[1]]$widths)), "mm")
# Add an empty column of "abs(diff(widths)) mm" width on the right of
# legend box for gA (the smaller legend box)
gA$grobs[[15]] <- gtable_add_cols(gA$grobs[[15]], unit(abs(diff(c(leg1, leg2))), "mm"))
# Combine the plots
g = gridExtra::rbind.gtable(gA, gB, size = "max")
# Draw it
grid.newpage()
grid.draw(g)
The cowplot package also has the align_plots function for this purpose (output not shown),
both2 <- align_plots(p1, p2, align="hv", axis="tblr")
p1x <- ggdraw(both2[[1]])
p2x <- ggdraw(both2[[2]])
save_plot("cow1.png", p1x)
save_plot("cow2.png", p2x)
and also plot_grid which saves the plots to the same file.
library(cowplot)
both <- plot_grid(p1, p2, ncol=1, labels = c("A", "B"), align = "v")
save_plot("cow.png", both)
As #hadley suggests, rbind.gtable should be able to handle this,
grid.draw(rbind(ggplotGrob(p1), ggplotGrob(p2), size="last"))
however, the layout widths should ideally be size="max", which doesn't cope well with some types of grid units.
Just by chance, I noticed that Arun's solution he had suggested in his comments hasn't been picked up. I feel his simple and efficient approach is really worth to be illustrated.
Arun suggested to move the legend to the top or bottom:
ggplot(df, aes(x=factor(0), fill=x)) + geom_bar() + theme(legend.position = "bottom")
ggplot(df, aes(x=factor(0), fill=y)) + geom_bar() + theme(legend.position = "bottom")
Now, the plots have the same width as requested. In addition, the plot area is equally sized in both cases.
If there are more factors or even longer labels, it might become necessary to play around with the legend, e.g., to display the legend in two ore more rows. theme() and guide_legend() have several parameters to control the position and appearance of legends in ggplot2.
I created a little function based on the answer of #Sandy.
same.size.ggplot <- function(vector.string.graph, # a vector of strings which correspond to Robject ggplot graphs
reference.string.graph, # a string of a Robject ggplot graphs where height and/or height will be taken for reference
width = T, # if you wanna adapat only the width
height = F # if you wanna adapat only the height
) {
# example: same.size.ggplot(p0rep(c("a", "b"), thre), "a30")
which(vector.string.graph %in% reference.string.graph)
newref <- ggplotGrob(get(reference.string.graph))
ref.width <- newref$widths
ref.height <- newref$heights
assign(reference.string.graph, newref, env = parent.frame(1))
for(i in seq_along(vector.string.graph)) {
if(vector.string.graph[i] != reference.string.graph) {
new <- ggplotGrob(get(vector.string.graph[i]))
if( width ) {
new$widths <- ref.width
}
if( height ) {
new$heights <- ref.height
}
assign(vector.string.graph[i], new, env = parent.frame(1))
}
}
}
p1 <- ggplot(data.frame(x=c("a","b","c"),y=c("happy","sad","ambivalent about life")),aes(x=factor(0),fill=x)) + geom_bar()
p2 <- ggplot(data.frame(x=c("a","b","c"),y=c("happy","sad","ambivalent about life")),aes(x=factor(0),fill=y)) + geom_bar()
p3 <- ggplot(data.frame(x=c("a","b","c"),y=c("Crazy happy","sad","Just follow the flow")),aes(x=factor(0),fill=y)) + geom_bar()
grid.arrange(p1, p2, p3, ncol = 1)
same.size.ggplot(c("p1", "p2", "p3"), "p2") # same as same.size.ggplot(c("p2", "p3"), "p1")
grid.arrange(p1, p2, p3, ncol = 1)
Before
After
You could also use the patchwork-package for that:
require(ggplot2)
require(patchwork)
# data
df = data.frame(x = c("a", "b", "c"),
y = c("happy", "sad", "ambivalent about life"))
p1 = ggplot(df, aes(x=factor(0), fill=x)) + geom_bar()
p2 = ggplot(df, aes(x=factor(0), fill=y)) + geom_bar()
# Patchwork 1: Does it automatically
p1 / p2
# Patchwork 2: Create a list
l = patchwork::align_patches(p1, p2)
How do i scale an axis with ggplot2 beginning at a certain point. Let's say we have a range from 0 to 100 and most values are within the range 1 to 10 and one value is at 100.
require('data.table')
require('ggplot2')
test <- data.table(x=1:10,y=c(seq(1,9),100))
ggplot(test, aes(x=x,y=y)) + geom_point(size=5)
I would like to create a graph with an y-scale from 1 to 10 by 1 and afterwards by 10 so the space between the value 9 and 100 gets "smaller" in the graph.
Update:
The way of eipi10 works perfect for what i want to achieve. Just one more detail i am struggling with. How do i get rid of the 2nd legend and keep the right ratio in the final plot?
and the code for the plot:
test <- data.table(x=1:10,y=c(seq(1,9),100))
p1 = ggplot(test, aes(x=x,y=y,color=x)) +
geom_point(size=5) +
scale_x_continuous(limits=c(0,10)) +
coord_cartesian(ylim=c(-0.1,10)) +
scale_y_continuous(breaks=0:10) +
theme(plot.margin=unit(c(0,0.5,0,0),"lines"))
p2 = ggplot(test, aes(x=x,y=y,color=x)) +
geom_point(size=5) + #geom_point(size=5,show.legend=FALSE) +
scale_x_continuous(limits=c(0,10)) +
coord_cartesian(ylim=c(40,110)) +
scale_y_continuous(breaks=c(50,100)) +
theme(plot.margin=unit(c(0,0.5,-0.5,0), "lines"),
axis.title.x=element_blank(),
axis.ticks.x=element_blank(),
axis.text.x=element_blank(),
legend.position="none") +
labs(y="")
gA <- ggplotGrob(p1)
gB <- ggplotGrob(p2)
maxWidth = grid::unit.pmax(gA$widths[2:5], gB$widths[2:5])
gA$widths[2:5] <- as.list(maxWidth)
gB$widths[2:5] <- as.list(maxWidth)
grid.arrange(gB, gA, ncol=1, heights=c(0.15,0.85))
Update 2:
An example of the final result. Thanks again to eipi10 and his great support!
A log transformation will do that:
require('data.table')
require('ggplot2')
library(scales)
test <- data.table(x=1:10,y=c(seq(1,9),100))
ggplot(test, aes(x=x,y=y)) +
geom_point(size=5) +
scale_y_log10(breaks=c(1,3,10,30,100))
UPDATE: There's no easy way to do a broken axis with ggplot2 (because ggplot2 doesn't allow you to (easily) do things that are considered bad practice), but here's a way to get what you're looking for. (Just don't tell Hadley I told you.)
library(data.table)
library(ggplot2)
library(scales)
library(grid)
library(gridExtra)
test <- data.table(x=1:10,y=c(seq(1,9),100))
The overall strategy is to make two separate plots, one for y>=10 and one for y<10 and then put them together. We'll change the plot margins in order to control the amount of space between the top of the bottom plot and the bottom of the top plot. We'll also get rid of the x-axis ticks and labels on the top plot.
Bottom plot (y < 10):
p1 = ggplot(test[test$y<10,], aes(x=x,y=y)) +
geom_point(size=5) +
scale_x_continuous(limits=c(0,10)) +
coord_cartesian(ylim=c(-0.1,10)) +
scale_y_continuous(breaks=0:10) +
theme(plot.margin=unit(c(0,0.5,0,0),"lines"))
Top plot (y >= 10). For this one, we get rid of the x axis labels and tick marks:
p2 = ggplot(test[test$y>=10,], aes(x=x,y=y)) +
geom_point(size=5) +
scale_x_continuous(limits=c(0,10)) +
coord_cartesian(ylim=c(10.0,110)) +
scale_y_continuous(breaks=c(50,100)) +
theme(plot.margin=unit(c(0,0.5,-0.5,0), "lines"),
axis.title.x=element_blank(),
axis.ticks.x=element_blank(),
axis.text.x=element_blank()) +
labs(y="")
Left align the two plots (based on this SO answer):
gA <- ggplotGrob(p1)
gB <- ggplotGrob(p2)
maxWidth = grid::unit.pmax(gA$widths[2:5], gB$widths[2:5])
gA$widths[2:5] <- as.list(maxWidth)
gB$widths[2:5] <- as.list(maxWidth)
Arrange both plots together. The heights argument determines the proportion of vertical space allotted to each plot:
grid.arrange(gB, gA, ncol=1, heights=c(0.15,0.85))
UPDATE 2: To include a legend, but also ensure that the plots are properly right justified, do the following:
1) Run the code in your updated question to create plots p1 and p2, where only p1 has a legend.
2) Extract legend as a separate grob using the function below (from this SO answer).
3) Remove the legend from p1.
4) Lay out the plots and the legend using grid.arrange and arrangeGrob.
# Function to extract the legend as a stand-alone grob
g_legend<-function(a.gplot){
tmp <- ggplot_gtable(ggplot_build(a.gplot))
leg <- which(sapply(tmp$grobs, function(x) x$name) == "guide-box")
legend <- tmp$grobs[[leg]]
legend
}
# Extract the legend from p1
leg = g_legend(p1)
# Remove the legend from p1
p1 = p1 + theme(legend.position="none")
# Left justify the two plots
gA <- ggplotGrob(p1)
gB <- ggplotGrob(p2)
maxWidth = grid::unit.pmax(gA$widths[2:5], gB$widths[2:5])
gA$widths[2:5] <- as.list(maxWidth)
gB$widths[2:5] <- as.list(maxWidth)
# Lay out the plots and the legend
grid.arrange(arrangeGrob(gB, gA, ncol=1, heights=c(0.15,0.85)),
leg, ncol=2, widths=c(0.9,0.1))
I'm trying to arrange plots for publication with the use of cowplot package.
I just want the panels to be equally sized and labelled.
Reproducible example
library(ggplot2)
library(cowplot)
gg1 <- ggplot(mtcars)+
geom_point(aes(x=mpg,y=hp))+
theme_bw()+
theme(aspect.ratio=1)
gg2 <- ggplot(mtcars)+
geom_point(aes(x=mpg,y=hp,fill=cyl))+
facet_wrap(~cyl,ncol=2)+
theme_bw()+
theme(aspect.ratio=1,
legend.position='none')
output <- plot_grid(gg1,gg2, labels = c('A','B'),label_size = 20)
print(output)
The code produces this plot.
As you may see, neither the horizontal axises match nor do the upper edges of the panels.
The argument align from cowplot does not work with faceted plots.
Any ideas?
Since this is one of the highest voted question regarding cowplot and complex alignments, I wanted to point out that cowplot now does have some functionality for aligning faceted plots. (I'm the package author.) However, they don't work in this particular case!
For example, this works (using the axis option in plot_grid()):
gg1 <- ggplot(mtcars) +
geom_point(aes(x=mpg, y=hp)) +
theme_bw()
gg2 <- ggplot(mtcars)+
geom_point(aes(x=mpg, y=hp, fill=cyl)) +
facet_wrap(~cyl, ncol=2) +
theme_bw() +
theme(legend.position='none')
plot_grid(gg1, gg2, labels = c('A','B'), label_size = 20,
align = 'h', axis = 'tb')
We can also do this the following, to get a different type of alignment (depending on whether you want the facet strip to be counted as part of the plot or not):
plot_grid(gg1, gg2, labels = c('A', 'B'), label_size = 20,
align = 'h', axis = 'b')
Now why did I say it doesn't work for this case? Because, if you look at the original code in the question, you'll see that there was a theme(aspect.ratio=1) setting that I removed. cowplot can align plots as long as you don't force a specific aspect ratio, because the method it uses to align plots typically modifies the aspect ratio of the individual plots.
Here's a hack until someone comes up with a more elegant answer: You can use grid.arrange from the gridExtra package to change the relative sizes of the two plots so that the axes line up. The w parameter in the code below is what controls that by giving the left-hand plot a bit more of the horizontal width, thereby making it relatively larger, when compared with the right-hand plot.
library(gridExtra)
w = 0.512
grid.arrange(gg1, gg2, widths=c(w,1-w), ncol=2)
You can also use arrangeGrob and textGrob to add the "A" and "B" titles to each plot.
w = 0.512
grid.arrange(arrangeGrob(textGrob("A", x=0.13, gp=gpar(fontface="bold", cex=1.4)),
gg1, heights=c(0.03,0.97)),
arrangeGrob(textGrob("B", x=0.13, gp=gpar(fontface="bold", cex=1.4)),
gg2, heights=c(0.03,0.97)),
widths=c(w,1-w), ncol=2)
In either case, you need to adjust w by hand to get the plots to line up (which is what makes this method, shall we say, sub-optimal). The appropriate value for w will change depending on the physical size of the plot. w=0.512 seemed to work well when I saved the plot below as a png of 1000 x 500 pixels.
A better answer will probably involve something analogous to this SO answer, but adapted for lining up facetted and non-facetted plots (or, more generally, plots that don't have a one-to-one correspondence between their constituent grobs).
here's a solution based on this idea
library(ggplot2)
library(grid)
library(gridExtra)
library(gtable)
gtable_frame <- function(g, width=unit(1,"null"), height=unit(1,"null")){
panels <- g[["layout"]][grepl("panel", g[["layout"]][["name"]]), ]
ll <- unique(panels$l)
tt <- unique(panels$t)
fixed_ar <- g$respect
if(fixed_ar) { # there lies madness, want to align despite aspect ratio constraints
ar <- as.numeric(g$heights[tt[1]]) / as.numeric(g$widths[ll[1]])
height <- width * ar
g$respect <- FALSE
}
core <- g[seq(min(tt), max(tt)), seq(min(ll), max(ll))]
top <- g[seq(1, min(tt)-1), ]
bottom <- g[seq(max(tt)+1, nrow(g)), ]
left <- g[, seq(1, min(ll)-1)]
right <- g[, seq(max(ll)+1, ncol(g))]
fg <- nullGrob()
lg <- if(length(left)) g[seq(min(tt), max(tt)), seq(1, min(ll)-1)] else fg
rg <- if(length(right)) g[seq(min(tt), max(tt)), seq(max(ll)+1,ncol(g))] else fg
grobs = list(fg, g[seq(1, min(tt)-1), seq(min(ll), max(ll))], fg,
lg, g[seq(min(tt), max(tt)), seq(min(ll), max(ll))], rg,
fg, g[seq(max(tt)+1, nrow(g)), seq(min(ll), max(ll))], fg)
widths <- unit.c(sum(left$widths), width, sum(right$widths))
heights <- unit.c(sum(top$heights), height, sum(bottom$heights))
all <- gtable_matrix("all", grobs = matrix(grobs, ncol=3, nrow=3, byrow = TRUE),
widths = widths, heights = heights)
all[["layout"]][5,"name"] <- "panel" # make sure knows where the panel is for nested calls
if(fixed_ar) all$respect <- TRUE
all
}
p1 <- ggplot(mtcars)+
geom_point(aes(x=mpg,y=hp))+
theme_bw()+
theme(aspect.ratio=1)
p2 <- ggplot(mtcars)+
geom_point(aes(x=mpg,y=hp,fill=cyl))+
facet_wrap(~cyl,ncol=2)+
theme_bw()+
theme(aspect.ratio=1,
legend.position='none')
g1 <- ggplotGrob(p1)
g2 <- ggplotGrob(p2)
fg1 <- gtable_frame(g1)
fg2 <- gtable_frame(g2)
grid.newpage()
grid.draw(cbind(fg1, fg2))
Note that the gtable_frame function wraps plots based on their panels, but excluding the panel strips by design (I find it more pleasant).
Update: egg package is on CRAN now
https://cran.r-project.org/web/packages/egg/index.html
I just want to add that #baptiste has created a great experimental package egg, which accomplishes what he wrote in his answer:
Install it from github (https://github.com/baptiste/egg)
library("devtools")
install_github("baptiste/egg")
Then simply do
library("egg")
ggarrange(gg1, gg2, ncol=2)
You can add labels manually:
ap <- ggarrange(gg1,gg2, ncol=2)
ggdraw(ap) + draw_plot_label(label=c("a","b"), x=c(0,0.5), y=c(1,1))
(When I tried to first add the labels to the individual plots, the plots didn't get arranged properly.)
I have a simpler solution sticking with plot_grid and the original example. However some may feel it is a bit of a cheat.
One can fine-tune aligning plots with cowplot:plot_grid by adding nested NULL plots and adjusting their height/width ratios. This is applied below:
gg3<-plot_grid(NULL,gg2, NULL, align = 'h', nrow = 3, rel_heights = c(0.06,1,0.06))
plot_grid(gg1,gg3, labels = c('A','B'),label_size = 20)
I am attempting to arrange multiple ggplot2 plots into one output/grid. I'd like the plots (without considering the labels) to be the same size. I have found a way to do this, but now I'd like to adjust the space between the plots.
For example:
In this plot, I'd like to reduce the amount of space between the two plots. I've tried adjusting margins, removing ticks, etc. This has removed some of the space.
Is there a way to have more control of the spacing adjustment between plots in situations such as these?
library(MASS)
data(iris)
library(ggplot2)
library(grid)
library(gridExtra)
p1 <- ggplot(iris,aes(Species,Sepal.Width))+geom_violin(fill="light gray")+geom_boxplot(width=.1) +coord_flip() +
theme(axis.title.y = element_blank()) + ylab("Sepal Width")
p2 <- ggplot(iris,aes(Species,Petal.Width))+geom_violin(fill="light gray")+geom_boxplot(width=.1) + coord_flip() +
theme(axis.title.y = element_blank(), axis.text.y=element_blank()) + ylab("Petal Width")
p11 <- p1 + theme(plot.margin = unit(c(-0.5,-0.5,-0.5,-0.5),"mm"))
p22 <- p2 + theme(plot.margin = unit(c(-0.5,-0.5,-0.5,-0.5),"mm"), axis.ticks.y=element_blank())
# https://stackoverflow.com/questions/24709307/keep-all-plot-components-same-size-in-ggplot2-between-two-plots
# make plots the same size, even with different labels
gl <- lapply(list(p11,p22), ggplotGrob)
widths <- do.call(unit.pmax, lapply(gl, "[[", "widths"))
heights <- do.call(unit.pmax, lapply(gl, "[[", "heights"))
lg <- lapply(gl, function(g) {g$widths <- widths; g$heights <- heights; g})
# https://stackoverflow.com/questions/1249548/side-by-side-plots-with-ggplot2-in-r?lq=1
grid.arrange(lg[[1]],lg[[2]], ncol=2) #in gridExtra
You have set the 'widths' to be the maximums of the two plots. This means that the widths for the y-axis of the 'Petal Widths' plot will be the same as the widths of the y-axis of the 'Sepal Widths' plot.
One way to adjust the spacing is, first, to combine the two grobs into one layout, deleting the y-axis and left margin of the second plot:
# Your code, but using p1 and p2, not the plots with adjusted margins
gl <- lapply(list(p1, p2), ggplotGrob)
widths <- do.call(unit.pmax, lapply(gl, "[[", "widths"))
heights <- do.call(unit.pmax, lapply(gl, "[[", "heights"))
lg <- lapply(gl, function(g) {g$widths <- widths; g$heights <- heights; g})
# New code
library(gtable)
gt = cbind(lg[[1]], lg[[2]][, -(1:3)], size = "first")
Then the width of the remaining space between the two plots can be adjusted:
gt$widths[5] = unit(2, "lines")
# Draw the plot
grid.newpage()
grid.draw(gt)
How to make the width of bars and spaces between them fixed for several barplots using ggplot, having different number of bars on each plot?
Here is a failed try:
m <- data.frame(x=1:10,y=runif(10))
ggplot(m, aes(x,y)) + geom_bar(stat="identity")
ggplot(m[1:3,], aes(x,y)) + geom_bar(stat="identity")
Adding width=1 to geom_bar(...) doesn't help as well. I need the second plot automatically to have less width and the same bar width and spaces as the first one.
Edit:
It appears the OP simply wants this:
library(gridExtra)
grid.arrange(p1,arrangeGrob(p2,widths=c(1,2),ncol=2), ncol=1)
I am not sure, if it's possible to pass absolute widths to geom_bar. So, here is an ugly hack:
set.seed(42)
m <- data.frame(x=1:10,y=runif(10))
p1 <- ggplot(m, aes(x,y)) + geom_bar(stat="identity")
p2 <- ggplot(m[1:3,], aes(x,y)) + geom_bar(stat="identity")
g1 <- ggplotGrob(p1)
g2 <- ggplotGrob(p2)
I used str to find the correct grob and child. You could use more sophisticated methods to generalize this if necessary.
#store the old widths
old.unit <- g2$grobs[[4]]$children[[2]]$width[[1]]
#change the widths
g2$grobs[[4]]$children[[2]]$width <- rep(g1$grobs[[4]]$children[[2]]$width[[1]],
length(g2$grobs[[4]]$children[[2]]$width))
#copy the attributes (units)
attributes(g2$grobs[[4]]$children[[2]]$width) <- attributes(g1$grobs[[4]]$children[[2]]$width)
#position adjustment (why are the bars justified left???)
d <- (old.unit-g2$grobs[[4]]$children[[2]]$width[[1]])/2
attributes(d) <- attributes(g2$grobs[[4]]$children[[2]]$x)
g2$grobs[[4]]$children[[2]]$x <- g2$grobs[[4]]$children[[2]]$x+d
#plot
grid.arrange(g1,g2)
Wrapped the other suggestions in a function that only requires a single graph.
fixedWidth <- function(graph, width=0.1) {
g2 <- graph
#store the old widths
old.unit <- g2$grobs[[4]]$children[[2]]$width[[1]]
original.attibutes <- attributes(g2$grobs[[4]]$children[[2]]$width)
#change the widths
g2$grobs[[4]]$children[[2]]$width <- rep(width,
length(g2$grobs[[4]]$children[[2]]$width))
#copy the attributes (units)
attributes(g2$grobs[[4]]$children[[2]]$width) <- original.attibutes
#position adjustment (why are the bars justified left???)
d <- (old.unit-g2$grobs[[4]]$children[[2]]$width[[1]])/2
attributes(d) <- attributes(g2$grobs[[4]]$children[[2]]$x)
g2$grobs[[4]]$children[[2]]$x <- g2$grobs[[4]]$children[[2]]$x+d
return(g2)
}