Change the y limits ( especially the minimum) with Vlnplot - r

I would like to draw a violin plot from my single cell data.
I am using this function :
Vlnplot(object, features, cols = NULL, pt.size = 0.1)
But I would like to change the y axis to 3000-10000 instead of 0-70000.
They only propose to change the y max but not the mean
Does someone have an idea how to do it ?

The VlnPlot function in the Seurat R package uses ggplot2 to draw the violin plot. This means we can modify the y-axis using scale_y_continuous.
In your case, to change the y-axis of your violin plot to 3000-10000, we would write:
VlnPlot(object, features, cols = NULL, pt.size = 0.1) + scale_y_continuous(limits = c(3000,10000))
To show you a reproducible example, we can draw a violin plot using the pbmc_small dataset from the Seurat package:
VlnPlot(pbmc_small, "CD3E")
The plot above has a default axis of 0 to around 6.3. Here is how the same plot looks like after altering the y-axis using scale_y_continuous, in which I zoom in between 0 and 3:
VlnPlot(pbmc_small, "CD3E") + scale_y_continuous(limits = c(0,3))
Many of the other visualizations in the Seurat package also use ggplot2, so you can make all types of cosmetic changes to them using various ggplot2 commands (themes, axis labels, colors, etc.)

Related

Is it possible to over-ride the x axis range in R package ggbio when using autoplot and ensdb transcripts?

I am trying to use ggbio to plot gene transcripts. I want to plot a very specific range so it matches my ggplot2 plots. The problem is my example plot ends up having range of 133,567,500-133,570,000 regardless of the GRange and whether I specify xlim or not.
This example should only plot a small bit of intron (the thin arrowed line) but instead plots the full 2 exons and intron in between. I believe autoplot wants to plot the entire transcript or transcripts present in the range and widens the range to accommodate for that.
library(EnsDb.Hsapiens.v86)
library(ggbio)
ensdb <- EnsDb.Hsapiens.v86
mut<-GRanges("10", IRanges(133568909, 133569095))
gene <- autoplot(ensdb, which=mut, names.expr="gene_name",xlim=c(133568909,133569095))
gene.gg <- gene#ggplot
png("test_gene_plot_5.png")
gene.gg
dev.off()
Is there any way to over-ride this? I've looked at the manual page for autoplot and I couldn't narrow down an option that would fix it. Others have said to use xlim, but that does not seem to change anything
I like ggbio because it can make a ggplot2 object to be plotted along with other ggplot2 objects. I have not seen an example for that with other approaches like Gvis. But I would entertain other approaches if they could be combined with my existing plots.
Thanks!
Amy
It kind of depends wether you want clipped or squished data. Usually autoplot outputs a ggplot object at some point that can be manipulated as such.
For squished data:
library(GenomicRanges) # just to be sure start and end work
gene#ggplot +
scale_x_continuous(limits = c(start(mut), end(mut)), oob = scales::squish)
For clipped data:
gene#ggplot +
coord_cartesian(xlim = c(start(mut), end(mut)))
But to be totally honest, I'm unsure wether this is the most informative way to communicate that you are plotting the internals of an intron.
Alternatively, I've written a gene model geom at some point that doesn't work through the autoplot methods (which can sometimes be a pain if you want to customise everything). Downside is that you'd have to do some manual gene searching and setting aesthetics. Upside is that it works like most other geoms and is therefore easy to combine with some other data.
library(ggnomics) # from: https://github.com/teunbrand/ggnomics
# Finding a gene's exons manually
my_gene <- transcriptsByOverlaps(EnsDb.Hsapiens.v86, mut)
my_gene <- exonsByOverlaps(EnsDb.Hsapiens.v86, my_gene)
my_gene <- as.data.frame(my_gene)
some_other_data <- data.frame(
x = seq(start(mut), end(mut), by = 10),
y = cumsum(rnorm(19))
)
ggplot(some_other_data) +
geom_line(aes(x, y)) +
geom_genemodel(data = my_gene,
aes(xmin = start, xmax = end,
y = max(some_other_data$y) + 1,
group = 1, strand = strand)) +
coord_cartesian(xlim = c(start(mut), end(mut)))
Hope that helped!

Axis breaks in ggplot histogram in R [duplicate]

I have data that is mostly centered in a small range (1-10) but there is a significant number of points (say, 10%) which are in (10-1000). I would like to plot a histogram for this data that will focus on (1-10) but will also show the (10-1000) data. Something like a log-scale for th histogram.
Yes, i know this means not all bins are of equal size
A simple hist(x) gives
while hist(x,breaks=c(0,1,1.1,1.2,1.3,1.4,1.5,1.6,1.7,1.8,1.9,2,3,4,5,7.5,10,15,20,50,100,200,500,1000,10000))) gives
none of which is what I want.
update
following the answers here I now produce something that is almost exactly what I want (I went with a continuous plot instead of bar-histogram):
breaks <- c(0,1,1.1,1.2,1.3,1.4,1.5,1.6,1.7,1.8,1.9,2,4,8)
ggplot(t,aes(x)) + geom_histogram(colour="darkblue", size=1, fill="blue") + scale_x_log10('true size/predicted size', breaks = breaks, labels = breaks)![alt text][3]
the only problem is that I'd like to match between the scale and the actual bars plotted. There two options for doing that : the one is simply use the actual margins of the plotted bars (how?) then get "ugly" x-axis labels like 1.1754,1.2985 etc. The other, which I prefer, is to control the actual bins margins used so they will match the breaks.
Log scale histograms are easier with ggplot than with base graphics. Try something like
library(ggplot2)
dfr <- data.frame(x = rlnorm(100, sdlog = 3))
ggplot(dfr, aes(x)) + geom_histogram() + scale_x_log10()
If you are desperate for base graphics, you need to plot a log-scale histogram without axes, then manually add the axes afterwards.
h <- hist(log10(dfr$x), axes = FALSE)
Axis(side = 2)
Axis(at = h$breaks, labels = 10^h$breaks, side = 1)
For completeness, the lattice solution would be
library(lattice)
histogram(~x, dfr, scales = list(x = list(log = TRUE)))
AN EXPLANATION OF WHY LOG VALUES ARE NEEDED IN THE BASE CASE:
If you plot the data with no log-transformation, then most of the data are clumped into bars at the left.
hist(dfr$x)
The hist function ignores the log argument (because it interferes with the calculation of breaks), so this doesn't work.
hist(dfr$x, log = "y")
Neither does this.
par(xlog = TRUE)
hist(dfr$x)
That means that we need to log transform the data before we draw the plot.
hist(log10(dfr$x))
Unfortunately, this messes up the axes, which brings us to workaround above.
Using ggplot2 seems like the most easy option. If you want more control over your axes and your breaks, you can do something like the following :
EDIT : new code provided
x <- c(rexp(1000,0.5)+0.5,rexp(100,0.5)*100)
breaks<- c(0,0.1,0.2,0.5,1,2,5,10,20,50,100,200,500,1000,10000)
major <- c(0.1,1,10,100,1000,10000)
H <- hist(log10(x),plot=F)
plot(H$mids,H$counts,type="n",
xaxt="n",
xlab="X",ylab="Counts",
main="Histogram of X",
bg="lightgrey"
)
abline(v=log10(breaks),col="lightgrey",lty=2)
abline(v=log10(major),col="lightgrey")
abline(h=pretty(H$counts),col="lightgrey")
plot(H,add=T,freq=T,col="blue")
#Position of ticks
at <- log10(breaks)
#Creation X axis
axis(1,at=at,labels=10^at)
This is as close as I can get to the ggplot2. Putting the background grey is not that straightforward, but doable if you define a rectangle with the size of your plot screen and put the background as grey.
Check all the functions I used, and also ?par. It will allow you to build your own graphs. Hope this helps.
A dynamic graph would also help in this plot. Use the manipulate package from Rstudio to do a dynamic ranged histogram:
library(manipulate)
data_dist <- table(data)
manipulate(barplot(data_dist[x:y]), x = slider(1,length(data_dist)), y = slider(10, length(data_dist)))
Then you will be able to use sliders to see the particular distribution in a dynamically selected range like this:

Formatting and manipulating a plot from the R package "hexbin"

I generate a plot using the package hexbin:
# install.packages("hexbin", dependencies=T)
library(hexbin)
set.seed(1234)
x <- rnorm(1e6)
y <- rnorm(1e6)
hbin <- hexbin(
x = x
, y = y
, xbin = 50
, xlab = expression(alpha)
, ylab = expression(beta)
)
## Using plot method for hexbin objects:
plot(hbin, style = "nested.lattice")
abline(h=0)
This seems to generate an S4 object (hbin), which I then plot using plot.
Now I'd like to add a horizontal line to that plot using abline, but unfortunately this gives the error:
plot.new has not yet been called
I have also no idea, how I can manipulate e.g. the position of the axis labels (alpha and beta are within the numbers), change the position of the legend, etc.
I'm familiar with OOP, but so far I could not find out how plot() handles the object (does it call certain methods of the object?) and how I can manipulate the resulting plot.
Why can't I simply draw a line onto the plot?
How can I manipulate axis labels?
Use lattice version of hex bin - hexbinplot(). With panel you can add your line, and with style you can choose different ways of visualizing hexagons. Check help for hexbinplot for more.
library(hexbin)
library(lattice)
x <- rnorm(1e6)
y <- rnorm(1e6)
hexbinplot(x ~ y, aspect = 1, bins=50,
xlab = expression(alpha), ylab = expression(beta),
style = "nested.centroids",
panel = function(...) {
panel.hexbinplot(...)
panel.abline(h=0)
})
hexbin uses grid graphics, not base. There is a similar function, grid.abline, which can draw lines on plots by specifying a slope and intercept, but the co-ordinate system used is confusing:
grid.abline(325,0)
gets approximately what you want, but the intercept here was found by eye.
You will have more luck using ggplot2:
library(ggplot2)
ggplot(data,aes(x=alpha,y=beta)) + geom_hex(bins=10) + geom_hline(yintercept=0.5)
I had a lot of trouble finding a lot of basic plot adjustments (axis ranges, labels, etc.) with the hexbin library but I figured out how to export the points into any other plotting function:
hxb<-hexbin(x=c(-15,-15,75,75),
y=c(-15,-15,75,75),
xbins=12)
hxb#xcm #gives the x co-ordinates of each hex tile
hxb#ycm #gives the y co-ordinates of each hex tile
hxb#count #gives the cell size for each hex tile
points(x=hxb#xcm, y=hxb#ycm, pch=hxb#count)
You can just feed these three vectors into any plotting tool you normally use.. there is the usual tweaking of size scaling, etc. but it's far better than the stubborn hexplot function. The problem I found with the ggplot2 stat_binhex is that I couldn't get the hexes to be different sizes... just different colors.
if you really want hexagons, plotrix has a hexagon drawing function that i think is fine.

Customize Contour Labels in ggplot2

I'm relatively new to ggplot2, and I'm having trouble adding appropriate labels to my contours. I would love to be able to add the labels without the directlabels package, but I haven't found a way to, so if you know of a way to customize labels without directlabels, I would love to here it.
Using the classic volcano example, I can add labels to the default contour plot using the directlabels packet in the following way:
library(plyr)
library(ggplot2)
library(directlabels)
library(reshape)
volcano<-melt(volcano)
v<-ggplot(volcano, aes(x,y,z=z))
e<-v + stat_contour(aes(colour=..level..))
direct.label(e)
In the above example, the labels are added appropriately, but things become more complicated if I try to specify my own break points for the contours:
e<-v + stat_contour(aes(breaks=c(160, 170, 180), colour=..level..))
direct.label(e)
Now, the contours are specified by the breaks I have provided, but labels still appear for all of the default contours. How do I only plot only labels for the graphed contours?
A related issue, how would I plot labels for contour levels not included in the default? Say a break of 165:
e<-v + stat_contour(aes(breaks=c(165), colour=..level..))
direct.label(e)
Thanks for any help!
The current development version (directlabels_2013.6.15 with ggplot2_0.9.3.1) should fix your problem (as the author of the directlabels package explained to me). You can install it with:
install.packages("directlabels", repos="http://r-forge.r-project.org")
And then:
library(plyr)
library(ggplot2)
library(directlabels)
library(reshape)
volcano<-melt(volcano)
v<-ggplot(volcano, aes(X1,X2,z=value))
e<-v + stat_contour(aes(colour=..level..), breaks=c(165))
direct.label(e)
I noted several other limitations with simple workarounds:
the first ggplot call must contain the z aesthetic
this works only with the stat_contour (and not with the geom_contour)
the colour aesthetic must be defined in the stat_contour call and set to ..level..
Finally, if you want to control the label and contour line colours (black labels and blue contour lines for instance), you can achieved this as follow:
e<-v + stat_contour(aes(colour=..level..), colour = "blue", breaks=c(165))
e<-e + scale_colour_continuous(low = "#FF0000", high = "#FF0000")
direct.label(e)

How can I plot a histogram of a long-tailed data using R?

I have data that is mostly centered in a small range (1-10) but there is a significant number of points (say, 10%) which are in (10-1000). I would like to plot a histogram for this data that will focus on (1-10) but will also show the (10-1000) data. Something like a log-scale for th histogram.
Yes, i know this means not all bins are of equal size
A simple hist(x) gives
while hist(x,breaks=c(0,1,1.1,1.2,1.3,1.4,1.5,1.6,1.7,1.8,1.9,2,3,4,5,7.5,10,15,20,50,100,200,500,1000,10000))) gives
none of which is what I want.
update
following the answers here I now produce something that is almost exactly what I want (I went with a continuous plot instead of bar-histogram):
breaks <- c(0,1,1.1,1.2,1.3,1.4,1.5,1.6,1.7,1.8,1.9,2,4,8)
ggplot(t,aes(x)) + geom_histogram(colour="darkblue", size=1, fill="blue") + scale_x_log10('true size/predicted size', breaks = breaks, labels = breaks)![alt text][3]
the only problem is that I'd like to match between the scale and the actual bars plotted. There two options for doing that : the one is simply use the actual margins of the plotted bars (how?) then get "ugly" x-axis labels like 1.1754,1.2985 etc. The other, which I prefer, is to control the actual bins margins used so they will match the breaks.
Log scale histograms are easier with ggplot than with base graphics. Try something like
library(ggplot2)
dfr <- data.frame(x = rlnorm(100, sdlog = 3))
ggplot(dfr, aes(x)) + geom_histogram() + scale_x_log10()
If you are desperate for base graphics, you need to plot a log-scale histogram without axes, then manually add the axes afterwards.
h <- hist(log10(dfr$x), axes = FALSE)
Axis(side = 2)
Axis(at = h$breaks, labels = 10^h$breaks, side = 1)
For completeness, the lattice solution would be
library(lattice)
histogram(~x, dfr, scales = list(x = list(log = TRUE)))
AN EXPLANATION OF WHY LOG VALUES ARE NEEDED IN THE BASE CASE:
If you plot the data with no log-transformation, then most of the data are clumped into bars at the left.
hist(dfr$x)
The hist function ignores the log argument (because it interferes with the calculation of breaks), so this doesn't work.
hist(dfr$x, log = "y")
Neither does this.
par(xlog = TRUE)
hist(dfr$x)
That means that we need to log transform the data before we draw the plot.
hist(log10(dfr$x))
Unfortunately, this messes up the axes, which brings us to workaround above.
Using ggplot2 seems like the most easy option. If you want more control over your axes and your breaks, you can do something like the following :
EDIT : new code provided
x <- c(rexp(1000,0.5)+0.5,rexp(100,0.5)*100)
breaks<- c(0,0.1,0.2,0.5,1,2,5,10,20,50,100,200,500,1000,10000)
major <- c(0.1,1,10,100,1000,10000)
H <- hist(log10(x),plot=F)
plot(H$mids,H$counts,type="n",
xaxt="n",
xlab="X",ylab="Counts",
main="Histogram of X",
bg="lightgrey"
)
abline(v=log10(breaks),col="lightgrey",lty=2)
abline(v=log10(major),col="lightgrey")
abline(h=pretty(H$counts),col="lightgrey")
plot(H,add=T,freq=T,col="blue")
#Position of ticks
at <- log10(breaks)
#Creation X axis
axis(1,at=at,labels=10^at)
This is as close as I can get to the ggplot2. Putting the background grey is not that straightforward, but doable if you define a rectangle with the size of your plot screen and put the background as grey.
Check all the functions I used, and also ?par. It will allow you to build your own graphs. Hope this helps.
A dynamic graph would also help in this plot. Use the manipulate package from Rstudio to do a dynamic ranged histogram:
library(manipulate)
data_dist <- table(data)
manipulate(barplot(data_dist[x:y]), x = slider(1,length(data_dist)), y = slider(10, length(data_dist)))
Then you will be able to use sliders to see the particular distribution in a dynamically selected range like this:

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