I'd like to use ggplot2 to make a plot where the axis text size varies between labels- for example, larger font every five ticks with smaller font for the intervening ticks. I looked at using minor_breaks in scale_x_continuous, but I couldn't find a way to label the minor breaks.
The best I've got to work so far is a modification from this answer where I use bquote to pass an expression for the axis labels:
label_span <- 1:40
ShrinkIf <- Vectorize(function(val) {
if (val %% 5 == 0) return(as.character(val))
return(bquote(scriptstyle(.(as.character(val)))))
})
x_labels <- ShrinkIf(label_span)
x_labels <- purrr::invoke(expression, x_labels)
ggplot(mtcars, aes(x = mpg , y = hp)) +
geom_point() +
scale_x_continuous(breaks = label_span, labels = x_labels)
Is there a better way to go about this, or maybe a way with a little more control of the label size (or even font choice / text decoration, etc)? Thanks in advance for your help!
You can create a vector of text sizes and add it using element_text()
library(ggplot2)
ggplot(mtcars, aes(x = mpg, y = hp)) +
geom_point() +
theme(
axis.text.x = element_text(size = rep(c(12,24), 3))
)
Related
This question is motivated by a previous post illustrating various ways to change how axes scales are plotted in a ggplot figure, from the default exponential notation to the full integer value (when ones axes values are very large). While I am able to convert the axes scales from exponential notation to full values, I am unclear how one would achieve the same goal for the values appearing in the legend.
While I understand that one can manually change the length of the legend scale with "scale_color..." or "scale_fill..." followed by the "limits" argument, this does not appear to be a solution to getting my legend values to show "6000000000" rather than "6e+09" (or "0" rather than "0e+00" for that matter).
The following example should suffice. My hope is someone can point out how to implement the 'scales' package to apply for legend scales rather than axes scales.
Thanks very much.
library(ggplot2)
library(scales)
Data <- data.frame(
pi = c(2,71,828,1828,45904,523536,2874713,52662497,757247093,6999595749),
e = c(3,14,159,2653,58979,311599,7963468,54418516,1590576171, 99),
face = 1:10)
p <- ggplot(data = Data, aes(x=face, y=e, colour = pi))
myplot <- p + geom_point() +
scale_y_continuous(labels = comma) +
scale_color_gradientn(colours = rainbow(2), limits=c(0,7000000000))
myplot
Use the Comma formatter in scale_color_gradientn by setting labels = comma e.g.:
p <- ggplot(data = Data, aes(x=face, y=e, colour = pi))
myplot <- p + geom_point() +
scale_y_continuous(labels = comma) +
scale_color_gradientn(colours = rainbow(2), limits=c(0,7000000000), labels = comma)
myplot
I have a set of code that produces multiple plots using facet_wrap:
ggplot(summ,aes(x=depth,y=expr,colour=bank,group=bank)) +
geom_errorbar(aes(ymin=expr-se,ymax=expr+se),lwd=0.4,width=0.3,position=pd) +
geom_line(aes(group=bank,linetype=bank),position=pd) +
geom_point(aes(group=bank,pch=bank),position=pd,size=2.5) +
scale_colour_manual(values=c("coral","cyan3", "blue")) +
facet_wrap(~gene,scales="free_y") +
theme_bw()
With the reference datasets, this code produces figures like this:
I am trying to accomplish two goals here:
Keep the auto scaling of the y axis, but make sure only 1 decimal place is displayed across all the plots. I have tried creating a new column of the rounded expr values, but it causes the error bars to not line up properly.
I would like to wrap the titles. I have tried changing the font size as in Change plot title sizes in a facet_wrap multiplot, but some of the gene names are too long and will end up being too small to read if I cram them on a single line. Is there a way to wrap the text, using code within the facet_wrap statement?
Probably cannot serve as definite answer, but here are some pointers regarding your questions:
Formatting the y-axis scale labels.
First, let's try the direct solution using format function. Here we format all y-axis scale labels to have 1 decimal value, after rounding it with round.
formatter <- function(...){
function(x) format(round(x, 1), ...)
}
mtcars2 <- mtcars
sp <- ggplot(mtcars2, aes(x = mpg, y = qsec)) + geom_point() + facet_wrap(~cyl, scales = "free_y")
sp <- sp + scale_y_continuous(labels = formatter(nsmall = 1))
The issue is, sometimes this approach is not practical. Take the leftmost plot from your figure, for example. Using the same formatting, all y-axis scale labels would be rounded up to -0.3, which is not preferable.
The other solution is to modify the breaks for each plot into a set of rounded values. But again, taking the leftmost plot of your figure as an example, it'll end up with just one label point, -0.3
Yet another solution is to format the labels into scientific form. For simplicity, you can modify the formatter function as follow:
formatter <- function(...){
function(x) format(x, ..., scientific = T, digit = 2)
}
Now you can have a uniform format for all of plots' y-axis. My suggestion, though, is to set the label with 2 decimal places after rounding.
Wrap facet titles
This can be done using labeller argument in facet_wrap.
# Modify cyl into factors
mtcars2$cyl <- c("Four Cylinder", "Six Cylinder", "Eight Cylinder")[match(mtcars2$cyl, c(4,6,8))]
# Redraw the graph
sp <- ggplot(mtcars2, aes(x = mpg, y = qsec)) + geom_point() +
facet_wrap(~cyl, scales = "free_y", labeller = labeller(cyl = label_wrap_gen(width = 10)))
sp <- sp + scale_y_continuous(labels = formatter(nsmall = 2))
It must be noted that the wrap function detects space to separate labels into lines. So, in your case, you might need to modify your variables.
This only solved the first part of the question. You can create a function to format your axis and use scale_y_continous to adjust it.
df <- data.frame(x=rnorm(11), y1=seq(2, 3, 0.1) + 10, y2=rnorm(11))
library(ggplot2)
library(reshape2)
df <- melt(df, 'x')
# Before
ggplot(df, aes(x=x, y=value)) + geom_point() +
facet_wrap(~ variable, scale="free")
# label function
f <- function(x){
format(round(x, 1), nsmall=1)
}
# After
ggplot(df, aes(x=x, y=value)) + geom_point() +
facet_wrap(~ variable, scale="free") +
scale_y_continuous(labels=f)
scale_*_continuous(..., labels = function(x) sprintf("%0.0f", x)) worked in my case.
I am trying to build a horizontal bar chart.
library(ggplot2)
library(plyr)
salary <- read.csv('September 15 2015 Salary Information - Alphabetical.csv', na.strings = '')
head(salary)
salary$X <- NULL
salary$X.1 <- NULL
salary$Club <- as.factor(salary$Club)
levels(salary$Club)
salary$Base.Salary <- gsub(',', '', salary$Base.Salary)
salary$Base.Salary <- as.numeric(as.character(salary$Base.Salary))
salary$Base.Salary <- salary$Base.Salary / 1000000
salary <- ddply(salary, .(Club), transform, pos = cumsum(Base.Salary) - (0.5 * Base.Salary))
ggplot(salary, aes(x = Club, y = Base.Salary, fill = Base.Salary)) +
geom_bar(stat = 'identity') +
ylab('Base Salary in millions of dollars') +
theme(axis.title.y = element_blank()) +
coord_flip() +
geom_text(data = subset(salary, Base.Salary > 2), aes(label = Last.Name, y = pos))
(credits to this thread: Showing data values on stacked bar chart in ggplot2 for the text position calculation)
and the resulting plot is this:
I was thoroughly confused for a while, because I was using xlab to specify the label, and theme(axis.title.y = element_blank()) to hide the y label. However, this didn't work, and I got it to work by changing it to ylab. This seems rather confusing, is it intended?
This seems rather confusing, is it intended?
Yes.
Rather than using theme() to hide the y label, I think
labs(x = "My x label",
y = "")
is more straightforward.
When you flip x and y, they take their labels with them. If this weren't the case, a graph compared with and without coordinate flip would have incorrect axis labels in one of the two cases - which seems confusing and inconsistent. As-is, the labels will be correct always (with and without coord_flip).
Theming, on the other hand, is applied after-the-fact.
I tried to change the font to 10 for the labels of my bar plot in ggplot2 by doing something like this:
ggplot(data=file,aes(x=V1,y=V3,fill=V2)) +
geom_bar(stat="identity",position="dodge",colour="white") +
geom_text(aes(label=V2),position=position_dodge(width=0.9),
hjust=1.5,colour="white") +
theme_bw()+theme(element_text(size=10))
ggsave(filename="barplot.pdf",width=4,height=4)
but the resulting image has super big font size for the bar plot labels.
Then I thought of modifying in geom_text() with this:
geom_text(size=10,aes(label=V2),position=position_dodge(width=0.9),
hjust=1.5,colour="white")
The label font is even bigger...
I can change the size within geom_text to something like 3 and now it looks like font 10, similar to the axis labels.
I'm wondering what's going on? Does theme(text=element_text(size=10)) doesn't apply to labels?
And why size of 10 in geom_text() is different from that in theme(text=element_text()) ?
Here are a few options for changing text / label sizes
library(ggplot2)
# Example data using mtcars
a <- aggregate(mpg ~ vs + am , mtcars, function(i) round(mean(i)))
p <- ggplot(mtcars, aes(factor(vs), y=mpg, fill=factor(am))) +
geom_bar(stat="identity",position="dodge") +
geom_text(data = a, aes(label = mpg),
position = position_dodge(width=0.9), size=20)
The size in the geom_text changes the size of the geom_text labels.
p <- p + theme(axis.text = element_text(size = 15)) # changes axis labels
p <- p + theme(axis.title = element_text(size = 25)) # change axis titles
p <- p + theme(text = element_text(size = 10)) # this will change all text size
# (except geom_text)
For this And why size of 10 in geom_text() is different from that in theme(text=element_text()) ?
Yes, they are different. I did a quick manual check and they appear to be in the ratio of ~ (14/5) for geom_text sizes to theme sizes.
So a horrible fix for uniform sizes is to scale by this ratio
geom.text.size = 7
theme.size = (14/5) * geom.text.size
ggplot(mtcars, aes(factor(vs), y=mpg, fill=factor(am))) +
geom_bar(stat="identity",position="dodge") +
geom_text(data = a, aes(label = mpg),
position = position_dodge(width=0.9), size=geom.text.size) +
theme(axis.text = element_text(size = theme.size, colour="black"))
This of course doesn't explain why? and is a pita (and i assume there is a more sensible way to do this)
Take a look at the relevant entry in ggplot2's customization FAQ: https://ggplot2.tidyverse.org/articles/faq-customising.html#what-is-the-default-size-of-geom_text-and-how-can-i-change-the-font-size-of-geom_text
You can modify the default size of geom_text() by placing update_geom_defaults("text", list(size = X), where X is your choice of new size, at the beginning of your script.
I'm having some trouble exporting a simple scatterplot to a pdf file in ggplot2. Specifically when I set the tick mark length to a negative value (essential), the tick mark labels merge with the axis line (as shown below).
The figure appears normally in the plot window of rstudio but when I export to pdf the problem occurs. Altering vjust in axis.text.x doesn't seem to be helping at all. I've also tried manipulating the plot margins.
Is anyone aware of a way of moving the labels away from the axis in such a situation?
Hopefully the code below should replicate the issue.
data = data.frame(xvar = seq(1:20), yvar = seq(1:20), labvar = rep(c("A", "B"), 10))
require(ggplot2)
require(gridExtra)
p <- ggplot(data = data, aes(x = xvar, y = yvar)) + geom_point() +
facet_wrap(~labvar, scales = "fixed") +
theme_classic()+
theme(axis.ticks.length=unit(-0.1, "cm"),
axis.text.x=element_text(vjust = 0))
p
Try using axis.ticks.margin:
p + theme(axis.ticks.margin = unit(5, "lines"))
I notice that the documentation for ?theme now includes a list of all theme elements and what they do.