Top to bottom alignment of two ggplot2 figures - r

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)

Related

How to sensibly align two legends when using cowplot in R?

A similar question was asked here, however I cant adapt the answer to my issue.
I am trying to correctly align two legends when using cowplot. For example, if I create some data and a cowplot with two legends like so:
library(cowplot)
library(ggplot2)
# create some data
dat <- NULL
for(i in 1:20){
x <- LETTERS[1:5]
y <- paste0("var", seq(1,5))
dat[[i]] <- expand.grid(X=x, Y=y)
dat[[i]]$Z <- runif(25, 0, 1)
}
# plotting function
plotFun <- function(data){
ggplot(data, aes(X, Y, fill= Z)) +
geom_tile() +
theme(aspect.ratio = 1,
legend.justification = c(0,1),
axis.text.x=element_blank(),
axis.ticks.x=element_blank(),
axis.text.y=element_blank(),
axis.ticks.y=element_blank()) +
xlab("") + ylab("")
}
# set up to plot on a grid
allPlots <- lapply(dat, plotFun)
allPlotsAlter <- lapply(allPlots, function(x) x + theme(legend.position = "none"))
n <- length(allPlotsAlter)
nRow <- floor(sqrt(n))
plotGrid <- gridExtra::arrangeGrob(grobs=allPlotsAlter, nrow=nRow)
# create a different type of legend
newPlot <- ggplot(iris, aes(x = Sepal.Length, y = Petal.Length, fill = Species)) +
geom_bar(stat = 'identity') + theme(legend.justification = c(0,1))
# get both legends and combine
legend <- cowplot::get_legend(allPlots[[1]])
legend1 <- cowplot::get_legend(newPlot)
combineLegend <- cowplot::plot_grid(
legend,
legend1,
nrow = 2)
# now make plot
cowplot::plot_grid(plotGrid,
combineLegend,
rel_widths = c(0.9, 0.11),
ncol = 2)
That creates this type of plot:
As you can see, the two legends have quite a bit of vertical space between them and they are not centred with the plot.
Is there a way to align the two legends so they look something like this:
I'm not sure if it is possible using cowplot... or is there a way to maybe use ggplot's annotate to place the legends?
I would probably go for patchwork, as Stefan suggests, but within cowplot you probably need to adjust the legend margins:
theme_margin <- theme(legend.box.margin = margin(100, 10, 100, 10))
legend <- cowplot::get_legend(allPlots[[1]] + theme_margin)
legend1 <- cowplot::get_legend(newPlot + theme_margin)
combineLegend <- cowplot::plot_grid(
legend,
legend1,
nrow = 2)
# now make plot
cowplot::plot_grid(plotGrid,
combineLegend,
rel_widths = c(0.9, 0.11),
ncol = 2)
If switching to another package is an option for you I would suggest to use patchwork to glue your plots together. One feature offered by patchwork is that using plot_spacer you could easily add some empty panels above and below your legends to "move" them to the center and thereby getting rid of the empty space. Depending on your final result or the height of your final plot you probably have to play a bit around with the heights and/or widths arguments:
library(cowplot)
library(ggplot2)
library(patchwork)
set.seed(123)
# create some data
dat <- NULL
for (i in 1:20) {
x <- LETTERS[1:5]
y <- paste0("var", seq(1, 5))
dat[[i]] <- expand.grid(X = x, Y = y)
dat[[i]]$Z <- runif(25, 0, 1)
}
# plotting function
plotFun <- function(data) {
ggplot(data, aes(X, Y, fill = Z)) +
geom_tile() +
theme(
aspect.ratio = 1,
legend.justification = c(0, 1),
axis.text.x = element_blank(),
axis.ticks.x = element_blank(),
axis.text.y = element_blank(),
axis.ticks.y = element_blank()
) +
labs(x = NULL, y = NULL)
}
# set up to plot on a grid
allPlots <- lapply(dat, plotFun)
allPlotsAlter <- lapply(allPlots, function(x) x + theme(legend.position = "none"))
n <- length(allPlotsAlter)
nRow <- floor(sqrt(n))
plotGrid <- wrap_plots(grobs = allPlotsAlter, nrow = nRow)
# create a different type of legend
newPlot <- ggplot(iris, aes(x = Sepal.Length, y = Petal.Length, fill = Species)) +
geom_bar(stat = "identity") +
theme(legend.justification = c(0, 1))
# get both legends and combine
legend <- cowplot::get_legend(allPlots[[1]])
legend1 <- cowplot::get_legend(newPlot)
combineLegend <- plot_spacer() + legend + legend1 + plot_spacer() + plot_layout(ncol = 1, heights = c(.5, 1, 1, .5))
wrap_elements(plotGrid) + combineLegend + plot_layout(widths = c(4, 1))

Is it possible to add a third y-axis to ggplot2?

Is there a possibility to add a third y-axis to a plot with ggplot2?
I have three different datasources I want to display in the plot. I already added a second y-axis, for the next dataset the scale is again very different, why I'm looking now for a solution.
So far I only found how to add a second axis, for example as shown [here].(https://r-graph-gallery.com/line-chart-dual-Y-axis-ggplot2.html)
But I whether there is an possibility to add another one... Thank you!
This is equally clunky, but shows how it can be done from scratch using only CRAN resources.
library(cowplot)
library(patchwork)
p1 <- ggplot(df, aes(Sepal.Width, Sepal.Length)) +
geom_point() + theme(axis.line = element_line())
p2 <- ggplot(df, aes(Sepal.Width, Petal.Width)) + geom_point() +
theme(axis.line = element_line())
p3 <- ggplot(df, aes(Sepal.Width, Petal.Length)) +
geom_point(aes(color = "Petal.Length")) +
geom_point(aes(y = Sepal.Length/100, color = "Sepal.Length")) +
geom_point(aes(y = Petal.Width / 1000, color = "Petal.Width")) +
theme(axis.line = element_line(),
plot.margin = margin(10, 10, 10, 30))
wrap_elements(get_plot_component(p1, "ylab-l")) +
wrap_elements(get_y_axis(p1)) +
wrap_elements(get_plot_component(p2, "ylab-l")) +
wrap_elements(get_y_axis(p2)) +
p3 +
plot_layout(widths = c(3, 1, 3, 1, 40))
Data used
df <- iris
df$Sepal.Length <- df$Sepal.Length * 100
df$Petal.Width <- df$Petal.Width * 1000
This is a very clunky solution based on extracting elements from previously plotted graphs and editing grid objects. It may or not give you a workable solution.
source("https://raw.githubusercontent.com/davidearn/plague_growth/master/analysis/plots/3axes.R")
set.seed(101)
dd <- data.frame(x=rnorm(20),y=rnorm(20))
library(ggplot2)
gg0 <- ggplot(dd)
g1A <- gg0 + geom_point(aes(x,y))
g1B <- gg0 + geom_point(aes(x,10*y))
g1C <- gg0 + geom_point(aes(x,100*y))
## use return_gtable = TRUE if planning to add further axes
g2 <- combine_axes(g1A,g1B,add_pos="l", return_gtable=TRUE)
g3 <- combine_axes(g2,g1C,add_pos="l")
print(g3)

Inner ticks in ggplot

I want to add inner ticks to my plot given by a vector.
say my vector is myvec <- c(1,3,4:9, 12, 15)
and my plot:
library(ggplot2)
df <- data.frame(x=seq(1:100), y=sort(rexp(100, 2), decreasing = T))
ggplot(df, aes(x=x, y=y)) + geom_point() +
scale_y_continuous(limits = c(0, 4))
I now want to add inside facing ticks at x= myvec, y=0 in blue color. How do I do it?
Tried to work with this solution, but could not use the vector.
Annotate ggplot with an extra tick and label
Try This:
df2<- cbind.data.frame("myvec" = myvec, z= rep(0, length(myvec)))
ggplot(df, aes(x=x, y=y)) + geom_point() +
scale_y_continuous(limits = c(0, 4)) +
geom_point(data=df2, aes(x=myvec, y=z), shape = "\U2714", color = "blue", size= 2)

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))

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

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