Make ggplot panels the same height in ggarrange - r

I have two ggplots that I'm combining with ggarrange(). One plot has long labels, that I wrap with scale_x_discrete(labels = function(x) str_wrap(x, width = 10)), where str_wrap() is from the stringr package. However, when I combine them, the first panel is reduced in height to accommodate for the space required by the wrapped labels. I already tried all kinds of variations of adjusting the margins both in theme(plot.margin = margin()) as well as axis.text.x=element_text(margin = unit(c(), "cm")), to no avail. I'm probably missing something very obvious, but I just can't get the panels to match in height, regardless of how much space is needed by the axis labels.
Thanks!
plot1 <- ggplot(data=dat, aes(x=x, y=y)) +
theme_bw() +
geom_point(size=2) +
labs(x='', y='', title='') +
scale_x_discrete(labels = function(x) str_wrap(x, width = 10))
plot2 <- ggplot(data=dat, aes(x=x2, y=y2)) +
theme_bw() +
geom_point(size=2) +
labs(x='', y='', title='')
ggarrange(plot1, plot2, ncol=2)

it's doable within ggarrange using the argument align.
Here using the iris example from above
# The plots
plot1 <- ggplot(iris, aes(x = Species, y = Sepal.Length)) +
geom_boxplot() +
scale_x_discrete(labels = c("setosa" = "Setosa", "versicolor" = "Versicolor", "virginica" = "A very long name for \n Vircinica just to reproduce \n the problem"))
plot2 <- ggplot(iris, aes(x = Sepal.Length, fill = Species)) +
geom_density(alpha = 0.8) + theme(legend.position = "none")
Default:
ggarrange(plot1, plot2, ncol = 2)
With align:
ggarrange(plot1, plot2, ncol = 2, align = "h")
Apparently, I'm not allowed to post images so you'll have to click on the link or run the code.
Hope that helps!

One option to stick with ggarrange is to adjust the heights of your plots. To illustrate the case with iris data:
plot1 <- ggplot(iris, aes(x = Species, y = Sepal.Length)) +
geom_boxplot() +
scale_x_discrete(labels = c("setosa" = "Setosa", "versicolor" = "Versicolor", "virginica" = "A very long name for \n Vircinica just to reproduce \n the problem"))
plot2 <- ggplot(iris, aes(x = Sepal.Length, fill = Species)) +
geom_density(alpha = 0.8) + theme(legend.position = "none")
ggarrange(plot1, plot2, ncol = 2)
You can then use ggplotGrob and grid::unit.pmax to get the same hight for both plots:
pg1 <- ggplotGrob(plot1)
pg2 <- ggplotGrob(plot2)
maxHeight = grid::unit.pmax(pg1$heights, pg2$heights)
pg1$heights <- as.list(maxHeight)
pg2$heights <- as.list(maxHeight)
ggarrange(pg1, pg2, ncol = 2)

Related

Get all the legends on the top of the plot

I have a multiple plot within a plot, generated by ggpubr::ggarrange(). However the legends only appears for the first plot i.e., A and B. I wanted to get the legends for rest of the colours, C, D, E on the top. Setting common.legend = TRUE only gives the first two legends.
Thanks for the help!
library(ggpubr)
arranged_plot <- ggarrange(
plot_list[[1]] + rremove("ylab") + rremove("xlab") + rremove("x.text"),
plot_list[[2]] + rremove("ylab") + rremove("xlab") + rremove("axis.text"),
plot_list[[3]] + rremove("ylab") + rremove("xlab"),
plot_list[[4]] + rremove("ylab") + rremove("xlab") + rremove("y.text"),
labels = NULL, ncol = 2, nrow = 2,align = "hv",
font.label = list(size = 10, color = "black", face = "bold", family = NULL, position = "top"),
common.legend=TRUE)
I'm not sure how to do this with ggarrange, but if you're willing to look at other methods, here are two options:
Using patchwork (and collecting legends).
# sample data where each elem has cyl=4 and another cyl
mtcars$cyl <- factor(mtcars$cyl)
mtdat1 <- lapply(c(6, 8), function(CY) {
subset(mtcars, cyl %in% c(4, CY)) |>
transform(CY = CY)
})
plot_list <- lapply(mtdat1, function(dat) {
ggplot(dat, aes(mpg, disp, color = cyl)) +
geom_point() +
scale_color_manual(values = setNames(c("gray", "red", "blue"), c(4, 6, 8)), drop = FALSE)
})
library(patchwork)
plot_list[[1]] + plot_list[[2]] +
plot_layout(nrow = 1, guides = "collect") &
theme(legend.position = "top")
Facets.
# sample data, starting with `mtdat1` from above
mtdat2 <- do.call(rbind, args = mtdat1)
ggplot(mtdat2, aes(mpg, disp, color = cyl)) +
facet_wrap(~ CY) +
geom_point() +
scale_color_manual(values = setNames(c("gray", "red", "blue"), c(4, 6, 8)), drop = FALSE) +
theme(legend.position = "top")
If you prefer to not have the facet strips, we can remove those in a theme:
ggplot(mtdat2, aes(mpg, disp, color = cyl)) +
facet_wrap(~ CY) +
geom_point() +
scale_color_manual(values = setNames(c("gray", "red", "blue"), c(4, 6, 8)), drop = FALSE) +
theme(legend.position = "top", strip.text.x = element_blank())
I think there are two advantages to facets:
Simpler code, more efficient, allowing ggplot to handle everything in one step.
Since we don't explicitly free the scales (e.g., not doing scales="free"), the axes are all on the same scale, no need to explicitly control them. For comparisons as in your graph, this can be a big difference in visualizing the differences between levels. (Compare this plot with the first plot using patchwork, though those axis limits can easily be fixed as well.)

Add a combined legend when combining plots with different legends

I have three different subplotts, each with their own legend. I want to combine each of these 3 legends into one common legend at the bottom of the plot. I have found many similar questions combining the legends of different sub plots into one common legend when all the subplots had the same legend. Yet, not when the legends are different. Attempts to change the code were not succesful.
grid_arrange_shared_legend <- function(...) {
plots <- list(...)
g <- ggplotGrob(plots[[1]] + theme(legend.position = "bottom"))$grobs
legend <- g[[which(sapply(g, function(x) x$name) == "guide-box")]]
lheight <- sum(legend$height)
grid.arrange(
do.call(arrangeGrob, lapply(plots, function(x)
x + theme(legend.position="none"))),
legend,
ncol = 1,
heights = unit.c(unit(1, "npc") - lheight, lheight))
}
data = read.table("fermentation_run.csv", header=TRUE, sep=",", fileEncoding="UTF-8-BOM")
p1 <- ggplot(data, aes(x = time)) +
geom_line(aes(y = cdw*5, colour = "CDW"), size=1) +
geom_line(aes(y = glucose, colour = "glucose"), size=1) +
geom_step(aes(y = substrate, colour = "substrate"), size=1) +
theme_classic() + ylab("Concentration (g/l)") +
xlab("Time (h)") +
scale_colour_manual(values = c("grey", "red", "black"))
theme(legend.position="bottom", legend.title=element_blank())
p2 <- ggplot(data, aes(x=time)) +
geom_line(aes(y = alkyl, colour = "alkyl SS"), size=1) +
geom_line(aes(y = oleyl, colour = "oleyl alcohol"), size=1) +
theme_classic() +
xlab("Time (h)") +
ylab("Concentration (g/l)") +
scale_colour_manual(values = c("green", "blue"))
theme(legend.position="bottom", legend.title=element_blank())
p3 <- ggplot(data, aes(x=time)) +
geom_step(aes(y = aeration, colour="aeration"), size=1) +
geom_line(aes(y = do/2, colour="dissolved oxygen"), size=1) +
theme_classic() +
xlab("Time (h)") +
ylab("Aeration (lpm)") +
scale_y_continuous(sec.axis = sec_axis(~.*2, name = "Dissolved oxygen (%)")) +
theme(legend.position="bottom", legend.title=element_blank())
grid_arrange_shared_legend(p1, p2,p3)
This returns only the legend of the first plot and not of the three plots combined.
I think the key is to add all the legends in your first plot. To achieve this, you could add some fake rows in your data and label them according to your legends for all plots. Let's assume those legends are "a", "b", "c", "d", "e", and "f" in the following:
library(tidyverse)
# insert several rows with values outside your plot range
data <- add_row(mtcars,am=c(2, 3, 4, 5), mpg = 35, disp = 900)
data1<-data %>%
mutate (
by1 = factor(am, levels = c(0, 1, 2, 3, 4, 5),
labels = c("a", "b","c","d", "e","f")))
p1 <- ggplot(data1, aes(x = mpg, y=disp, col=by1)) +
geom_point() +
ylim(50,500)
You will get all the legends you need, and grid_arrange_shared_legend(p1, p2,p3) will pick up this. As you can see only "a" and "b" are for the first plot, and the rest are for other plots.
I don't have your data so I'll illustrate it with some basic datasets. The method isn't perfect with respect to some whitespace around the legends, but maybe someone in the comments knows a solution.
The answer I'm proposing is getting dirty with gtables and patchwork and internal functions thereof.
library(ggplot2)
library(grid)
library(patchwork) #https://github.com/thomasp85/patchwork
# Make plots as usual
g1 <- ggplot(iris, aes(Sepal.Width, Sepal.Length)) +
geom_point(aes(colour = Species))
g2 <- ggplot(mtcars, aes(mpg, disp)) +
geom_point(aes(colour = as.factor(cyl)))
# specify a legend position and a orientation for plots
position <- "bottom"
orientation <- "vertical"
# Add as many plots as you want to this list
plots <- list(g1, g2)
# Grab legends from plots in list
legends <- lapply(plots, function(p) {
p <- ggplotGrob(p + theme(legend.position = position))$grobs
p[[which(sapply(p, function(x) x$name) == "guide-box")]]
})
# Combine the legends
legend <- switch(position,
"bottom" = do.call(gtable:::cbind.gtable, legends),
"right" = do.call(gtable:::rbind.gtable, legends))
# Now make versions of the plots without the legend
stripped <- lapply(plots, function(p) p + theme(legend.position = "none"))
# Combine all the plots
stripped <- switch(orientation,
"horizontal" = do.call(patchwork:::ggplot_add.ggplot, stripped),
"vertical" = do.call(patchwork:::`/.ggplot`, stripped))
# Combine plots with legend
out <- switch(position,
"bottom" = stripped / legend,
"right" = stripped + legend)
out
Created on 2019-08-17 by the reprex package (v0.3.0)
If the whitespace really is a problem, you could supply a plot layout, but this would have to be a manual judgement to make:
out + plot_layout(heights = c(1,1,0.2))

Add empty plots to facet, and combine with another facet

Using this SO solution I created a facet with two "empty" plots, with the aim of combining with another group of facet_wrap plots, as shown below. The purpose is to have two y-axis labels for different unit measurements. How can I make the grid layout look like the top image, which produces the arrangement I want, but not the axis labels? This was accomplished with plot_grid with individual plots. My current output does not scale correctly and overlaps the other plots, as seen in the second image, but provides the axis labels.
I have example data below, just copy and run the code to input it.
library(ggplot2)
library(grid)
library(cowplot)
clipboard <- readClipboard()
test.data <- read.table(file = "clipboard", sep = ",", header=TRUE)
test.data1 <- test.data[1:24, ]
test.data2 <- test.data[25:32, ]
testplot1 <- ggplot(test.data1, aes(Station, value)) +
geom_point() +
labs(x = "Stations", y = "Scale A") +
theme(legend.position = "none", legend.title = element_blank()) +
facet_wrap( ~ constituent, ncol = 3, scales = "free_y")
testplot2 <- ggplot(test.data2, aes(Station, value)) +
geom_point() +
labs(x = "Stations", y = "Scale B") +
theme(legend.position = "none", legend.title = element_blank(), axis.title.y = element_text(hjust = 0.2)) +
facet_wrap( ~ constituent, ncol = 1, scales = "free_y")
blankplots <- ggplotGrob(testplot2)
rm_grobs <- blankplots$layout$name %in% c("panel-1-1", "panel-2-1", "strip-t-1-1", "strip-t-1-2")
blankplots$grobs[rm_grobs] <- NULL
blankplots$layout <- blankplots$layout[!rm_grobs, ]
grid.newpage()
emptygrids <- grid.draw(blankplots)
plot_grid(emptygrids, MPLOOplot1)
Example date is below:
Station,constituent,value
A1,A,1
B1,A,1
A1,B,2
B1,B,2
A1,C,3
B1,C,3
A1,D,4
B1,D,4
A1,E,5
B1,E,5
A1,F,6
B1,F,6
A1,G,7
B1,G,7
A1,H,8
B1,H,8
A1,I,9
B1,I,9
A1,J,10
B1,J,10
A1,K,11
B1,K,11
A1,L,1.4
B1,L,1.4
A1,Blank1,NA
B1,Blank1,NA
A1,Blank2,NA
B1,Blank2,NA
A1,XX,0.52
B1,XX,0.52
A1,YY,0.355
B1,YY,0.355
I'm not sure I understand exactly what you're trying to do, so let me know if this is what you had in mind. I wasn't sure what you wanted colour to be mapped to, so I just used constituent for this example.
library(gridExtra)
library(ggplot2)
library(dplyr)
library(cowplot)
theme_set(theme_classic())
testplot1 <- ggplot(test.data1, aes(Station, value, colour=constituent)) +
geom_point() +
labs(x = "Stations", y = "Scale A") +
theme(legend.title = element_blank()) +
facet_wrap( ~ constituent, ncol = 3, scales = "free_y") +
guides(colour=guide_legend(ncol=2))
testplot2 <- ggplot(test.data2 %>% filter(!grepl("Blank", constituent)),
aes(Station, value, colour=constituent)) +
geom_point() +
labs(x = "Stations", y = "Scale B") +
theme(legend.title = element_blank(),
axis.title.y = element_text(hjust = 0.2)) +
facet_wrap( ~ constituent, ncol = 1, scales = "free_y")
leg1 = get_legend(testplot1)
leg2 = get_legend(testplot2)
testplot1 = testplot1 + guides(colour=FALSE)
testplot2 = testplot2 + guides(colour=FALSE)
Now we lay out the plots and legends with grid.arrange. This requires some manual tweaking of the heights and widths.
grid.arrange(
arrangeGrob(
arrangeGrob(nullGrob(), leg2, leg1, nullGrob(), ncol=4, widths=c(1,4,4,1)),
testplot2, ncol=1, heights=c(4.2,5)
),
testplot1, ncol=2, widths=c(1.1,3))

How can I align multiple plots by their titles instead of plot area?

I'm using egg to align multiple plots on a page. I'm wondering if it's possible to align two columns by the titles a) and c) instead of plot area? Thanks!
Code:
library(egg)
library(grid)
p1 <- ggplot(mtcars, aes(mpg, wt, colour = factor(cyl))) +
geom_point() + ggtitle("a)")
p1
p2 <- ggplot(mtcars, aes(mpg, wt, colour = factor(cyl))) +
geom_point() + facet_wrap(~ cyl, ncol = 2, scales = "free") +
guides(colour = "none") +
theme() + ggtitle("b)")
p2
p3 <- ggplot(mtcars, aes(mpg, wt, colour = factor(cyl))) +
geom_point() + facet_grid(. ~ am, scales = "free") + guides(colour="none") +
ggtitle("c)")
p3
g1 <- ggplotGrob(p1)
g2 <- ggplotGrob(p2)
g3 <- ggplotGrob(p3)
fg1 <- gtable_frame(g1, debug = TRUE)
fg2 <- gtable_frame(g2, debug = TRUE)
fg12 <- gtable_frame(gtable_rbind(fg1, fg2),
width = unit(2, "null"),
height = unit(1, "null"))
fg3 <-
gtable_frame(
g3,
width = unit(2, "null"),
height = unit(1, "null"),
debug = TRUE
)
grid.newpage()
combined <- gtable_cbind(fg12, fg3)
grid.draw(combined)
Plot:
I found another way by using cowplot package
left_col <- cowplot::plot_grid(p1 + ggtitle(""), p2 + ggtitle(""),
labels = c('a)', 'b)'), label_size = 14,
ncol = 1, align = 'v', axis = 'lr')
cowplot::plot_grid(left_col, p3 + ggtitle(""),
labels = c('', 'c)'), label_size = 14,
align = 'h', axis = 'b')
See also here
Edit:
A recently developed package patchwork for ggplot2 can also get the job done
library(patchwork)
{
p1 + {p2} + patchwork::plot_layout(ncol = 1)
} / p3 + patchwork::plot_layout(ncol = 2)
Adding a blank dummy faceting variable to plot p1/ a) seems like the easiest solution
p1 <- ggplot(data.frame(mtcars, dummy=''),
aes(mpg, wt, colour = factor(cyl))) +
geom_point() + ggtitle("a)") +
facet_wrap(~dummy)

Specify plot height in plot_grid with 'hv' aligment: cowplot

I have been using the plot_grid command from cowplot to arrange my plots. I use the labeling feature, and my plots all look the same in that regard. However, when I 'hv' align some plots that have very different y-axis limits, such as the one below, it appears the height of the plot with shortest range of y is used.
If I just 'v' align the plot it looks better in some respects, but it is hard to resize the plot and have the labels looking good. I'd prefer the plot height not consider the x-axis labels, etc, like above.
Using gtables, I can get the desired width/height (below), but these leaves me without the consistent labels across all the figures in a document. Can I use the 'hv' alignment with cowplot and specify which plot height to use?
library(ggplot2)
library(dplyr)
library(scales)
library(grid)
library(cowplot)
data(iris)
iris <- iris %>% mutate(Petal.Width2 = ifelse(Species == "setosa", Petal.Width * 75, Petal.Width))
p1 <- ggplot(data=iris, aes(x = factor(Species), y=Sepal.Width)) +
geom_bar(stat="identity") +
labs(x = NULL, y = "Plot One") +
scale_y_continuous(labels = percent) +
theme(axis.text.x = element_blank(),
axis.title.y = element_text(vjust=1), plot.margin=unit(c(2,2,0,2),"mm"))
p2 <- ggplot(data=iris, aes(x = factor(Species), y=Petal.Width2)) + geom_bar(stat="identity") +
labs(x = NULL, y = "Plot Two") +
scale_y_continuous(labels = percent) +
theme(axis.text.x = element_blank(),
axis.title.y = element_text(vjust=1), plot.margin=unit(c(0,2,0,2),"mm"))
p3 <- ggplot(data=iris, aes(x = factor(Species), y=Petal.Length*0+.01)) + geom_bar(stat="identity") +
labs(x = "SPECIES", y = "The Third plot") +
scale_y_continuous(labels = percent) +
theme( axis.title.y = element_text(vjust=1, color="blue"), plot.margin=unit(c(0,2,0,2),"mm"),
axis.text.x = element_text(angle = 90, hjust=1, vjust=1,face ="italic", size=10))
plot_grid(p1,p2,p3,ncol=1, align="v", labels=c("A", "B", "C"))
# https://stackoverflow.com/a/27408589/1670053
plots <- list(p1, p2, p3)
grobs = lapply(plots, ggplotGrob)
g = do.call(rbind, c(grobs, size="first"))
g$widths = do.call(unit.pmax, lapply(grobs, "[[", "widths"))
grid.newpage()
grid.draw(g)
it's easy as to add labels,
plots <- list(p1, p2, p3)
grobs = lapply(plots, ggplotGrob)
library(gridExtra)
g = do.call(rbind, grobs) # uses gridExtra::rbind.gtable
panels <- g$layout[g$layout$name=="panel",]
g <- gtable::gtable_add_grob(g, lapply(LETTERS[1:nrow(panels)],
textGrob, vjust=1, y=1,
gp=gpar(fontface=2)),
t=panels$t, l=2)
grid.newpage()
grid.draw(g)

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