Ordering in ggplot2 [plotting pvals by BP for each chr] - r

I'm trying to plot points along the genome: there will be plot points for every chromosome. My data file looks like this:
CHROM BP P DP
1 234567 0.0000555 30
.....
Y 12345678 0.09 14
I'm using gglopt2 to plot P values, coloured by DP, for each chromosome, using the following:
mc.points <- ggplot(sample,aes(x = BP,y = P, colour =DP)) +
geom_point() +
labs(x = "Chromosome",y = "P") +
scale_color_gradient2(low = "green", high = "red")
However, instead of being plotted at each BP in the right chromosomal order, its being plotted by BP without any thought of chromosome number.
Is there a way to sort the data to make this happen (ie order by chromosome then BP)? I've tried to make CHROM and BP factors but this seems to crash R. In addition, if this is possible is there a way to label the X-tics on the X axis as chromosome numbers rather than BP (similar to a Manhattan plot).
I can provide dummy data if need be but this is quite long.
Just to provide an update: facet_grid seems to solve my problem but I was wondering whether I can transform this? It splits the grids by chromosome, but doesn't plot them on the same x-axis in consecutive order - But plots 22 different plots using the same scale x-axis. Any solutions?????

Have you tried something this untested code before the plot:
sample$BP <- factor(sample$BP,
levels=sample[ !duplicated(sample[,"BP"]), "BP"][
order(sample[!duplicated(sample[ ,"BP"]), "chromosome"] )]
)
Would have been easier and perhaps more compact if you included a suitable sample for testing. In the future you should NOT use the name `sample" since it is an important R function name.

Related

Making a line graph with certain X + Y values expressed differently with lines of 33 user IDs in R

I'm trying to put ActivityDate on the X Axis, and Calories on the Y Axis, relating to how 33 different users ranged in their calorie burnings daily. I'm new to ggplot and visualizations as you can tell, so I'd appreciate the most basic solution that I can understand. Thank you so much.
I really tried several iterations of this code, and each one of them weren't quite right in how the visualization turned out. Here are a couple of my thoughts:
##first and foremost:
install.packages("tidyverse") install.packages("here") library(tidyverse) library(here)
Attempt 1 Bar Graph
ggplot(data=trimmed_dactivity) + geom_bar(mapping=aes(x=Id, color=ActivityDate))
Attempt 1 Bar Graph
##Not probably the best for stakeholders, but if I could maybe have the bars a little closer together that might help, so I tried to identify the unique IDs. Perhaps the reason why they are so small is that they appear in long number format, and are not sequential, so it could be adding the extra space and making the bars so small because of the spaces of empty sequential numbers.
Attempt 2 Bar Graph
UId <- unique("Id") ggplot(data=trimmed_dactivity) + geom_bar(mapping=aes(x=UId, color=ActivityDate))
Attempt 2 Bar Graph
##Facepalm, definitely not what I was looking for at all, but that was my effort to solve the above problem.
Attempt 3 Bar Graph
ggplot(data=trimmed_dactivity) + geom_bar(mapping=aes(x=ActivityDate, fill=Id)) + theme(axis.text.x = element_text(angle=45))
Attempt 3 Bar Graph
##The fill function does not work, and on the y-axis if you will, I don't know what "count" is referring to in this case, so could be useful except for those two issues.
##Finally, I switch to a line graph
Attempt 4 Line Graph
ggplot(data=trimmed_dactivity) + geom_line(mapping=aes(x=ActivityDate, y=Calories)) + theme(axis.text.x = element_text(angle=45))
Attempt 4 Line Graph
##Now what I get is separate lines going up and down, and what I want is 33 separate lines representing unique Id numbers to travel along the x axis for time, and rise in the y axis for calories. Of course I'm not sure how to do that...
Any help with what I'm missing on this journey here?
what I want is 33 separate lines representing unique Id numbers…
It sounds like you want a spaghetti plot. To make one, map Id to color (or to group if you don’t want each id to be colored differently).
library(ggplot2)
ggplot(fakedata, aes(ActivityDate, Calories)) +
geom_line(aes(color = factor(Id)), show.legend = FALSE)
Example data:
set.seed(13)
fakedata <- expand.grid(
Id = 1:33,
ActivityDate = seq(as.Date("2016-04-13"), length.out = 10, by = "day")
)
fakedata$Calories <- round(rnorm(330, 2500, 500))

Histogram: Combine continuous and discrete values in ggplot2

I have a set of times that I would like to plot on a histogram.
Toy example:
df <- data.frame(time = c(1,2,2,3,4,5,5,5,6,7,7,7,9,9, ">10"))
The problem is that one value is ">10" and refers to the number of times that more than 10 seconds were observed. The other time points are all numbers referring to the actual time. Now, I would like to create a histogram that treats all numbers as numeric and combines them in bins when appropriate, while plotting the counts of the ">10" at the side of the distribution, but not in a separate plot. I have tried to call geom_histogram twice, once with the continuous data and once with the discrete data in a separate column but that gives me the following error:
Error: Discrete value supplied to continuous scale
Happy to hear suggestions!
Here's a kind of involved solution, but I believe it best answers your question, which is that you are desiring to place next to typical histogram plot a bar representing the ">10" values (or the values which are non-numeric). Critically, you want to ensure that you maintain the "binning" associated with a histogram plot, which means you are not looking to simply make your scale a discrete scale and represent a histogram with a typical barplot.
The Data
Since you want to retain histogram features, I'm going to use an example dataset that is a bit more involved than that you gave us. I'm just going to specify a uniform distribution (n=100) with 20 ">10" values thrown in there.
set.seed(123)
df<- data.frame(time=c(runif(100,0,10), rep(">10",20)))
As prepared, df$time is a character vector, but for a histogram, we need that to be numeric. We're simply going to force it to be numeric and accept that the ">10" values are going to be coerced to be NAs. This is fine, since in the end we're just going to count up those NA values and represent them with a bar. While I'm at it, I'm creating a subset of df that will be used for creating the bar representing our NAs (">10") using the count() function, which returns a dataframe consisting of one row and column: df$n = 20 in this case.
library(dplyr)
df$time <- as.numeric(df$time) #force numeric and get NA for everything else
df_na <- count(subset(df, is.na(time)))
The Plot(s)
For the actual plot, you are asking to create a combination of (1) a histogram, and (2) a barplot. These are not the same plot, but more importantly, they cannot share the same axis, since by definition, the histogram needs a continuous axis and "NA" values or ">10" is not a numeric/continuous value. The solution here is to make two separate plots, then combine them with a bit of magic thanks to cowplot.
The histogram is created quite easily. I'm saving the number of bins for demonstration purposes later. Here's the basic plot:
bin_num <- 12 # using this later
p1 <- ggplot(df, aes(x=time)) + theme_classic() +
geom_histogram(color='gray25', fill='blue', alpha=0.3, bins=bin_num)
Thanks to the subsetting previously, the barplot for the NA values is easy too:
p2 <- ggplot(df_na, aes(x=">10", y=n)) + theme_classic() +
geom_col(color='gray25', fill='red', alpha=0.3)
Yikes! That looks horrible, but have patience.
Stitching them together
You can simply run plot_grid(p1, p2) and you get something workable... but it leaves quite a lot to be desired:
There are problems here. I'll enumerate them, then show you the final code for how I address them:
Need to remove some elements from the NA barplot. Namely, the y axis entirely and the title for x axis (but it can't be NULL or the x axes won't line up properly). These are theme() elements that are easily removed via ggplot.
The NA barplot is taking up WAY too much room. Need to cut the width down. We address this by accessing the rel_widths= argument of plot_grid(). Easy peasy.
How do we know how to set the y scale upper limit? This is a bit more involved, since it will depend on the ..count.. stat for p1 as well as the numer of NA values. You can access the maximum count for a histogram using ggplot_build(), which is a part of ggplot2.
So, the final code requires the creation of the basic p1 and p2 plots, then adds to them in order to fix the limits. I'm also adding an annotation for number of bins to p1 so that we can track how well the upper limit setting works. Here's the code and some example plots where bin_num is set at 12 and 5, respectively:
# basic plots
p1 <- ggplot(df, aes(x=time)) + theme_classic() +
geom_histogram(color='gray25', fill='blue', alpha=0.3, bins=bin_num)
p2 <- ggplot(df_na, aes(x=">10", y=n)) + theme_classic() +
geom_col(color='gray25', fill='red', alpha=0.3) +
labs(x="") + theme(axis.line.y=element_blank(), axis.text.y=element_blank(),
axis.title.y=element_blank(), axis.ticks.y=element_blank()
) +
scale_x_discrete(expand=expansion(add=1))
#set upper y scale limit
max_count <- max(c(max(ggplot_build(p1)$data[[1]]$count), df_na$n))
# fix limits for plots
p1 <- p1 + scale_y_continuous(limits=c(0,max_count), expand=expansion(mult=c(0,0.15))) +
annotate('text', x=0, y=max_count, label=paste('Bins:', bin_num)) # for demo purposes
p2 <- p2 + scale_y_continuous(limits=c(0,max_count), expand=expansion(mult=c(0,0.15)))
plot_grid(p1, p2, rel_widths=c(1,0.2))
So, our upper limit fixing works. You can get really crazy playing around with positioning, etc and the plot_grid() function, but I think it works pretty well this way.
Perhaps, this is what you are looking for:
df1 <- data.frame(x=sample(1:12,50,rep=T))
df2 <- df1 %>% group_by(x) %>%
dplyr::summarise(y=n()) %>% subset(x<11)
df3 <- subset(df1, x>10) %>% dplyr::summarise(y=n()) %>% mutate(x=11)
df <- rbind(df2,df3 )
label <- ifelse((df$x<11),as.character(df$x),">10")
p <- ggplot(df, aes(x=x,y=y,color=x,fill=x)) +
geom_bar(stat="identity", position = "dodge") +
scale_x_continuous(breaks=df$x,labels=label)
p
and you get the following output:
Please note that sometimes you could have some of the bars missing depending on the sample.

How to Plot Bar Charts for a Categorical Variable Against an Analytical Variable in R

I'm struggling with how to do something with R that comes very easily to me in Excel: so I'm sure this is something quite basic but I'm just not aware of the equivalent method in R.
In essence, I have a two variables in my dataset: a categorical variable which has a list of names, and an analytical variable that has the frequency corresponding to that particular observation.
Something like this:
Name Freq
==== =========
X 100
Y 200
and so on.
I would like to plot a bar chart with the names listed on the X-Axis (X, Y and so on) and bars of height corresponding to the relevant value of the Freq. variable for that observation.
This is something very trivial with Excel; I can just select the relevant cells and create a bar chart.
However, in R I just can't seem to figure out how to do this! The bar charts in R seems to be univariate only and doesn't behave the way I want it to. Trying to plot the two variables results in a scatter plot which is not what I'm going for.
Is there something very basic I'm missing here, or is R just not capable of performing this task?
Any pointers will be much helpful.
Edited to Add:
I was primarily trying to use base R's plot function to get the job done.
Using, plot(dataset1$Name, dataset1$Freq) does not lead to a bar graph but a scatter-plot instead.
First the data.
dat <- data.frame(Name = c("X", "Y"), Freq = c(100, 200))
With base R.
barplot(dat$Freq, names.arg = dat$Name)
If you want to display a long list of names.arg, maybe the best way is to customize your horizontal axis with function staxlab from package plotrix. Here are two example plots.
One, with the axis labels rotated 45 degrees.
set.seed(3)
Name <- paste0("Name_", LETTERS[1:10])
dat2 <- data.frame(Name = Name, Freq = sample(100:200, 10))
bp <- barplot(dat2$Freq)
plotrix::staxlab(1, at = bp, labels = dat2$Name, srt = 45)
Another, with the labels spread over 3 lines.
bp <- barplot(dat2$Freq)
plotrix::staxlab(1, at = bp, labels = dat2$Name, nlines = 3)
Add colors with argument col. See help("par").
With ggplot2.
library(ggplot2)
ggplot(dat, aes(Name, Freq)) +
geom_bar(stat = "identity")
To add colors you have the aesthetics colour (for the contour of the bars) and fill (for the interior of the bars).

R - Time series data with ggplot2

I have a time series dataset in which the x-axis is a list of events in reverse chronological order such that an observation will have an x value that looks like "n-1" or "n-2" all the way down to 1.
I'd like to make a line graph using ggplot that creates a smooth, continuous line that connects all of the points, but it seems when I try to input my data, the x-axis is extremely wonky.
The code I am currently using is
library(ggplot2)
theoretical = data.frame(PA = c("n-1", "n-2", "n-3"),
predictive_value = c(100, 99, 98));
p = ggplot(data=theoretical, aes(x=PA, y=predictive_value)) + geom_line();
p = p + scale_x_discrete(labels=paste("n-", 1:3, sep=""));
The fitted line and grid partitions that would normally appear using ggplot are replaced by no line and wayyy too many partitions.
When you use geom_line() with a factor on at least one axis, you need to specify a group aesthetic, in this case a constant.
p = ggplot(data=theoretical, aes(x=PA, y=predictive_value, group = 1)) + geom_line()
p = p + scale_x_discrete(labels=paste("n-", 1:3, sep=""))
p
If you want to get rid of the minor grid lines you can add
theme(panel.grid.minor = element_blank())
to your graph.
Note that it can be a little risky, scale-wise, to use factors on one axis like this. It may work better to use a typical continuous scale, and just relabel the points 1, 2, and 3 with "n-1", "n-2", and "n-3".

ggplot boxplots with scatterplot overlay (same variables)

I'm an undergrad researcher and I've been teaching myself R over the past few months. I just started trying ggplot, and have run into some trouble. I've made a series of boxplots looking at the depth of fish at different acoustic receiver stations. I'd like to add a scatterplot that shows the depths of the receiver stations. This is what I have so far:
data <- read.csv(".....MPS.csv", header=TRUE)
df <- data.frame(f1=factor(data$Tagging.location), #$
f2=factor(data$Station),data$Detection.depth)
df2 <- data.frame(f2=factor(data$Station), data$depth)
df$f1f2 <- interaction(df$f1, df$f2) #$
plot1 <- ggplot(aes(y = data$Detection.depth, x = f2, fill = f1), data = df) + #$
geom_boxplot() + stat_summary(fun.data = give.n, geom = "text",
position = position_dodge(height = 0, width = 0.75), size = 3)
plot1+xlab("MPS Station") + ylab("Depth(m)") +
theme(legend.title=element_blank()) + scale_y_reverse() +
coord_cartesian(ylim=c(150, -10))
plot2 <- ggplot(aes(y=data$depth, x=f2), data=df2) + geom_point()
plot2+scale_y_reverse() + coord_cartesian(ylim=c(150,-10)) +
xlab("MPS Station") + ylab("Depth (m)")
Unfortunately, since I'm a new user in this forum, I'm not allowed to upload images of these two plots. My x-axis is "Stations" (which has 12 options) and my y-axis is "Depth" (0-150 m). The boxplots are colour-coded by tagging site (which has 2 options). The depths are coming from two different columns in my spreadsheet, and they cannot be combined into one.
My goal is to to combine those two plots, by adding "plot2" (Station depth scatterplot) to "plot1" boxplots (Detection depths). They are both looking at the same variables (depth and station), and must be the same y-axis scale.
I think I could figure out a messy workaround if I were using the R base program, but I would like to learn ggplot properly, if possible. Any help is greatly appreciated!
Update: I was confused by the language used in the original post, and wrote a slightly more complicated answer than necessary. Here is the cleaned up version.
Step 1: Setting up. Here, we make sure the depth values in both data frames have the same variable name (for readability).
df <- data.frame(f1=factor(data$Tagging.location), f2=factor(data$Station), depth=data$Detection.depth)
df2 <- data.frame(f2=factor(data$Station), depth=data$depth)
Step 2: Now you can plot this with the 'ggplot' function and split the data by using the `col=f1`` argument. We'll plot the detection data separately, since that requires a boxplot, and then we'll plot the depths of the stations with colored points (assuming each station only has one depth). We specify the two different plots by referencing the data from within the 'geom' functions, instead of specifying the data inside the main 'ggplot' function. It should look something like this:
ggplot()+geom_boxplot(data=df, aes(x=f2, y=depth, col=f1)) + geom_point(data=df2, aes(x=f2, y=depth), colour="blue") + scale_y_reverse()
In this plot example, we use boxplots to represent the detection data and color those boxplots by the site label. The stations, however, we plot separately using a specific color of points, so we will be able to see them clearly in relation to the boxplots.
You should be able to adjust the plot from here to suit your needs.
I've created some dummy data and loaded into the chart to show you what it would look like. Keep in mind that this is purely random data and doesn't really make sense.

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