plot multiple plots with legends from other plots beside - r

I have three plots p1, p2 and p3.
I would like to combine p2 and p3 and add the legends of p2 and p1 on the right side above each other. In the following example the legends are identical. In the real data they are differend.
I use ggplot2 and cowplot
# plot 1
p1 <- ggplot(iris, aes(Sepal.Length, fill = Species)) +
geom_density(alpha = .7)
# plot 2
p2 <- ggplot(iris, aes(Sepal.Width, fill = Species)) +
geom_density(alpha = .7)
# plot 3
p3 <- ggplot(iris, aes(Petal.Width, fill = Species)) +
geom_density(alpha = .7)
# legend1
legend1 <- get_legend(p1)
# legend2
legend2 <- get_legend(p2)
# combine plots
prow <- plot_grid( p2 + theme(legend.position="none"),
p3 + theme(legend.position="none"),
align = 'vh',
labels = c("a", "b"),
hjust = -1,
nrow = 1,
axis="1"
)
prow
# add legend1
p <- plot_grid( prow, legend1, rel_widths = c(1, .3))
p
# add legend2
plot_grid(p, legend2, rel_widths =c(1, .3))
This gives me this:
What I try to get is:
I tried to solve the problem using
+ theme(legend.position=c()
and
+ theme(legend.justification = "top"))
however, I could not get the desired plot.

You're actually very close. You can use ggdraw to achieve what you want. See ?get_legend for another example of this.
# combine plots
prow <- ggdraw(
plot_grid(
plot_grid(p2 + theme(legend.position="none") ,
p3 +theme(legend.position="none"),
align = 'vh',
labels = c("a", "b"),
hjust = -1,
nrow = 1,
axis="1"),
# as suggested by aosmith you can add additional columns to make legends appear closer
plot_grid(legend1, legend2,ncol=4),
# I also set the relative widths so the legend takes up less space
nrow=1, rel_widths = c(1,0.2))
)
prow

Related

Align a shared legend in cowplot

I'm looking to use the cowplot package to give two ggplots a shared legend. However, how can I center the shared legend when there's an even number of plots.
Here's some example code:
library(ggplot2)
library(cowplot)
library(rlang)
# down-sampled diamonds data set
dsamp <- diamonds[sample(nrow(diamonds), 1000), ]
# function to create plots
plot_diamonds <- function(xaes) {
xaes <- enquo(xaes)
ggplot(dsamp, aes(!!xaes, price, color = clarity)) +
geom_point() +
theme_half_open(12) +
# we set the left and right margins to 0 to remove
# unnecessary spacing in the final plot arrangement.
theme(plot.margin = margin(6, 0, 6, 0))
}
# make two plots
p1 <- plot_diamonds(carat)
p2 <- plot_diamonds(depth) + ylab(NULL)
# arrange the three plots in a single row
prow <- plot_grid(
p1 + theme(legend.position="none"),
p2 + theme(legend.position="none"),
align = 'vh',
labels = c("A", "B"),
hjust = -1,
nrow = 1
)
prow
# extract a legend that is laid out horizontally
legend_b <- get_legend(
p1 +
guides(color = guide_legend(nrow = 1)) +
theme(legend.position = "bottom")
)
# add the legend underneath the row we made earlier. Give it 10%
# of the height of one plot (via rel_heights).
plot_grid(prow, legend_b, ncol = 1, rel_heights = c(1, .1))
Which produces this image:
As you can see, cow_plot puts the the legend is located underneath the left image. Is there a way to make this shared legend centered between the two images?
Change the theme like below;
legend_b <- get_legend( p1 +
guides(color = guide_legend(nrow = 1)) +
theme(legend.direction = "horizontal",
legend.justification="center",
legend.box.just = "bottom")
)

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))

Remove white space in ggarrange, ggplot2

Say I have three SQUARE plots p1 p2 p3 made from the ggplot2 package. I applied ggarrange command under ggpubr package to make a 1*3 plot after that. Here are the commands:
library(ggplot2)
library(ggpubr)
library(gridExtra)
data <- data.frame(matrix(seq(1, 30, 1), 2))
for(i in 1:5){
plot1 <- ggplot(data = data, aes(y = data[, (i*3-2)])) +
theme(aspect.ratio = 1)
plot2 <- ggplot(data = data, aes(y = data[, (i*3-1)])) +
theme(aspect.ratio = 1)
plot3 <- ggplot(data = data, aes(y = data[, (i*3)])) +
theme(aspect.ratio = 1)
p <- ggarrange(plot1, plot2, plot3,
ncol = 3, common.legend = TRUE, legend = "bottom")
grid.arrange(p, top = paste(colnames(data)[i]), heights = c(1, 1))
}
The rmarkdown output (below) shows a large white space below the arranged plots:
Is there any way to remove it? What I thought is to change the default size of canvas..

Decrease margins between plots when using cowplot

I would like to combine some graphs together using cowplot. But I cannot change the margin sizes. I want to use only one y-axes, but than the margin is still quite large, which I want to decrease. I have used the plot.margin code from ggplot, although that works when I look at the single plot, it doesn't seem to work when the plots are combined.
I have made some example code:
library(ggplot2)
library(cowplot)
x <- c("a", "b")
y1 <- c(3,6)
y2 <- c(10,15)
data1 <- data.frame(x,y1)
data2 <- data.frame(x, y2)
ylab1 <- ylab("Very nice y values")
xlab1 <- xlab("Very nice factors")
plot1 <- ggplot(data1, aes(x=x, y = y1)) +
geom_bar(stat ="identity", position=position_dodge(), fill = "grey")+
theme(plot.margin = unit(c(0.5,0.5,0.5,0.5), "cm")) + xlab1 + ylab1
plot1
ylab2 <- ylab("")
xlab2 <- xlab("Very nice factors")
plot2 <- ggplot(data2, aes(x=x, y = y2)) +
geom_bar(stat = "identity",position=position_dodge(), fill = "grey")+
theme(plot.margin = unit(c(0.5,0.5,0.5,-0.5), "cm")) + xlab2 + ylab2
plot2
plot3 <- plot_grid(plot1, plot2, labels = c("A", "B"), align = "hv",nrow = 1, ncol = 2)
plot3 # Quite large margin between the two plots
I am aware that I could avoid this problem by using facets, however my real plot is rather more complicated than this graph.
Increasing the space between plots in plot_grid was also addressed in this issue.
An extra interesting solution is the one suggested in this comment - try to add an extra empty plot between the two plots and adjust the relative columns widths:
plot4 <- plot_grid(plot1, NULL, plot2, rel_widths = c(1, 0, 1), align = "hv",
labels = c("A", "B"), nrow = 1)
plot4
Can even try negative values in rel_widths, which gives better results:
plot5 <- plot_grid(plot1, NULL, plot2, rel_widths = c(1, -0.1, 1), align = "hv",
labels = c("A", "B"), nrow = 1)
plot5
So, try a combination of adjusting the plot.margin (as answered by #J.Con) and adding an extra empty plot with tweaking rel_widths.
EDIT 2019-12-11
Also check out this comment of the author of cowplot (Claus Wilke):
For those kinds of problems I would now recommend the patchwork library. It's inherently difficult with plot_grid(), due to its underlying design
So, a fast example with patchwork based on their vignette Adding Annotation and Style goes like this:
library(patchwork)
plot3 <- plot1 + plot2 +
plot_annotation(tag_levels = 'A') &
theme(plot.tag = element_text(size = 8))
plot3
Created on 2019-12-11 by the reprex package (v0.3.0)
Your plot.margins were actually working against you. Set them to zero to fill up that white space.
plot1 <- ggplot(data1, aes(x=x, y = y1)) +
geom_bar(stat ="identity", position=position_dodge(), fill = "grey")+
theme(plot.margin = unit(c(0,0,0,0), "cm")) + xlab1 + ylab1
plot1
ylab2 <- ylab("")
xlab2 <- xlab("Very nice factors")
plot2 <- ggplot(data2, aes(x=x, y = y2)) +
geom_bar(stat = "identity",position=position_dodge(), fill = "grey")+
theme(plot.margin = unit(c(0,0,0,0), "cm")) + xlab2 + ylab2
plot2
plot3 <- plot_grid(plot1, plot2, labels = c("A", "B"), align = "hv",nrow = 1, ncol = 2)
plot3

Top to bottom alignment of two ggplot2 figures

I realize that the align.plots function from the ggExtra package has been deprecated and removed. However, I am using my own version as it seems to provide the specific functionality I need. I have looked into faceting to solve my problem but I don't think it will work for my particular issue. What seems to be the problem is that the top-to-bottom images don't align when I use coord_equal on one of them. This doesn't seem to affect left-to-right though. Here is a simplified (or at least as simple as I can make it) version of what I am trying to achieve.
Create some dummy data frames:
source('https://raw.github.com/jbryer/multilevelPSA/master/r/align.R')
require(psych)
df = data.frame(x=rnorm(100, mean=50, sd=10),
y=rnorm(100, mean=48, sd=10),
group=rep(letters[1:10], 10))
dfx = describe.by(df$x, df$group, mat=TRUE)[,c('group1', 'mean', 'n', 'min', 'max')]
names(dfx) = c('group', 'x', 'x.n', 'x.min', 'x.max')
dfy = describe.by(df$y, df$group, mat=TRUE)[,c('group1', 'mean', 'n', 'min', 'max')]
names(dfy) = c('group', 'y', 'y.n', 'y.min', 'y.max')
df2 = cbind(dfx, dfy[,2:ncol(dfy)])
range = c(0,100)
This will setup the three plots:
p1a = ggplot(df2, aes(x=x, y=y, colour=group)) + geom_point() +
opts(legend.position='none') +
scale_x_continuous(limits=range) + scale_y_continuous(limits=range)
p1 = p1a + coord_equal(ratio=1)
p2 = ggplot(df, aes(x=x, y=group, colour=group)) + geom_point() +
scale_x_continuous(limits=range) + opts(legend.position='none')
p3 = ggplot(df, aes(x=group, y=y, colour=group)) + geom_point() +
scale_y_continuous(limits=range) + opts(legend.position='none')
The alignment top to bottom does not work with coord_equal
grid_layout <- grid.layout(nrow=2, ncol=2, widths=c(1,2), heights=c(2,1))
grid.newpage()
pushViewport( viewport( layout=grid_layout, width=1, height=1 ) )
align.plots(grid_layout, list(p1, 1, 2), list(p3, 1, 1), list(p2, 2, 2))
Broken Plot http://bryer.org/alignplots1.png
The fix is to add respect=TRUE to the grid.layout call:
grid_layout <- grid.layout(nrow=2, ncol=2, widths=c(1,2), heights=c(2,1), respect=TRUE)
But if I don't use coord_equal the alignment works fine:
grid_layout <- grid.layout(nrow=2, ncol=2, widths=c(1,2), heights=c(2,1))
grid.newpage()
pushViewport( viewport( layout=grid_layout, width=1, height=1 ) )
align.plots(grid_layout, list(p1a, 1, 2), list(p3, 1, 1), list(p2, 2, 2))
Working Plot http://bryer.org/alignplots2.png
ggplot2 now has ggplotGrob(), which may help with this.
First, we need to update the code used to generate the plots:
p1a = ggplot(df2, aes(x=x, y=y, colour=group)) + geom_point() +
scale_x_continuous(limits=range) + scale_y_continuous(limits=range)
p1 = p1a + coord_equal(ratio=1) + theme_minimal() + theme(legend.position='none')
p2 = ggplot(df, aes(x=x, y=group, colour=group)) + geom_point() +
scale_x_continuous(limits=range) + theme_minimal() + theme(legend.position='none')
p3 = ggplot(df, aes(x=group, y=y, colour=group)) + geom_point() +
scale_y_continuous(limits=range) + theme_minimal() + theme(legend.position='none')
p4 <- ggplot(df, aes(x = group, y = y)) +
geom_blank() +
theme(line = element_blank(),
rect = element_blank(),
text = element_blank(),
title = element_blank())
p4 will be blank; we just need the grob to draw.
Then we load the grid package and draw the grobs in a list arranged in rows and columns using cbind() and rbind().
library(grid)
grid.newpage()
grid.draw(
cbind(
rbind(ggplotGrob(p3), ggplotGrob(p4), size = "first"),
rbind(ggplotGrob(p1), ggplotGrob(p2), size = "first"),
size = "first"))
I'm not sure if this method will let you plot p3 in a different width and p2 in a different height, as you have them in the original example; I normally need a grid of similarly-sized graphs, and haven't needed to figure out different sizes.
This answer is partially based on partially based on https://stackoverflow.com/a/17463184/393354
Here is an example:
m <- matrix(c(3, 1, 0, 2), 2, byrow = T)
lay <- gglayout(m, widths = c(1, 3), heights = c(3, 1))
ggtable(p1, p2, p3, layout = lay)
you can use this by
install.packages('devtools')
library(devtools)
dev_mode()
install_github("ggplot2", "kohske", "cutting-edge")
library(ggplot2)
note that this branch is experimental, so maybe there are bugs.
To solve the problem using the align.plots method, specify respect=TRUE on the layout call:
grid_layout <- grid.layout(nrow=2, ncol=2, widths=c(1,2), heights=c(2,1), respect=TRUE)

Resources