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I’m totally new to ggplot, relatively fresh with R and want to make a smashing ”before-and-after” scatterplot with connecting lines to illustrate the movement in percentages of different subgroups before and after a special training initiative. I’ve tried some options, but have yet to:
show each individual observation separately (now same values are overlapping)
connect the related before and after measures (x=0 and X=1) with lines to more clearly illustrate the direction of variation
subset the data along class and id using shape and colors
How can I best create a scatter plot using ggplot (or other) fulfilling the above demands?
Main alternative: geom_point()
Here is some sample data and example code using genom_point
x <- c(0,0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1) # 0=before, 1=after
y <- c(45,30,10,40,10,NA,30,80,80,NA,95,NA,90,NA,90,70,10,80,98,95) # percentage of ”feelings of peace"
class <- c(0,0,0,0,0,0,0,0,1,1,0,0,0,0,0,0,0,0,1,1) # 0=multiple days 1=one day
id <- c(1,1,2,3,4,4,4,4,5,6,1,1,2,3,4,4,4,4,5,6) # id = per individual
df <- data.frame(x,y,class,id)
ggplot(df, aes(x=x, y=y), fill=id, shape=class) + geom_point()
Alternative: scale_size()
I have explored stat_sum() to summarize the frequencies of overlapping observations, but then not being able to subset using colors and shapes due to overlap.
ggplot(df, aes(x=x, y=y)) +
stat_sum()
Alternative: geom_dotplot()
I have also explored geom_dotplot() to clarify the overlapping observations that arise from using genom_point() as I do in the example below, however I have yet to understand how to combine the before and after measures into the same plot.
df1 <- df[1:10,] # data before
df2 <- df[11:20,] # data after
p1 <- ggplot(df1, aes(x=x, y=y)) +
geom_dotplot(binaxis = "y", stackdir = "center",stackratio=2,
binwidth=(1/0.3))
p2 <- ggplot(df2, aes(x=x, y=y)) +
geom_dotplot(binaxis = "y", stackdir = "center",stackratio=2,
binwidth=(1/0.3))
grid.arrange(p1,p2, nrow=1) # GridExtra package
Or maybe it is better to summarize data by x, id, class as mean/median of y, filter out ids producing NAs (e.g. ids 3 and 6), and connect the points by lines? So in case if you don't really need to show variability for some ids (which could be true if the plot only illustrates tendencies) you can do it this way:
library(ggplot)
library(dplyr)
#library(ggthemes)
df <- df %>%
group_by(x, id, class) %>%
summarize(y = median(y, na.rm = T)) %>%
ungroup() %>%
mutate(
id = factor(id),
x = factor(x, labels = c("before", "after")),
class = factor(class, labels = c("one day", "multiple days")),
) %>%
group_by(id) %>%
mutate(nas = any(is.na(y))) %>%
ungroup() %>%
filter(!nas) %>%
select(-nas)
ggplot(df, aes(x = x, y = y, col = id, group = id)) +
geom_point(aes(shape = class)) +
geom_line(show.legend = F) +
#theme_few() +
#theme(legend.position = "none") +
ylab("Feelings of peace, %") +
xlab("")
Here's one possible solution for you.
First - to get the color and shapes determined by variables, you need to put these into the aes function. I turned several into factors, so the labs function fixes the labels so they don't appear as "factor(x)" but just "x".
To address multiple points, one solution is to use geom_smooth with method = "lm". This plots the regression line, instead of connecting all the dots.
The option se = FALSE prevents confidence intervals from being plotted - I don't think they add a lot to your plot, but play with it.
Connecting the dots is done by geom_line - feel free to try that as well.
Within geom_point, the option position = position_jitter(width = .1) adds random noise to the x-axis so points do not overlap.
ggplot(df, aes(x=factor(x), y=y, color=factor(id), shape=factor(class), group = id)) +
geom_point(position = position_jitter(width = .1)) +
geom_smooth(method = 'lm', se = FALSE) +
labs(
x = "x",
color = "ID",
shape = 'Class'
)
I've made this multiple histogram plot in ggplot and now I want to add a legend for both the light purple part and the dark purple part. I know the conventional way is to to it with aes, but I can't seem to figure out how I integrate this feature as one into my multiple histogram plot.
I don't shy manual labour, but more sophisticated solutions are preferred. Anyone help me out?
#dataframe
set.seed(20)
df <- data.frame(expl = rbinom(n=100, size = 1, prob=0.08),
resp = sample(50:100, size = 100, replace = T))
#graph
graph <- ggplot(data = df, aes(x = resp))
graph +
geom_histogram(fill = "#BEBADA", alpha = 0.5, bins = 10) +
geom_histogram(data = subset(df, expl == '1'), fill = "#BEBADA", bins = 10)
Your data is already in the long format that is well suited for ggplot; you just need to map expl to alpha. In general, if you find yourself making multiples of the same geom, you probably want to rethink either the shape of your data or your approach for feeding it into geoms.
library(tidyverse)
set.seed(20)
df <- data.frame(expl = rbinom(n=100, size = 1, prob=0.08),
resp = sample(50:100, size = 100, replace = T))
To map expl onto alpha, make it a factor, and then assign that to alpha inside your aes. Then you can set the alpha scale to values of 0.5 and 1.
ggplot(df, aes(x = resp, alpha = as.factor(expl))) +
geom_histogram(fill = "#bebada", bins = 10) +
scale_alpha_manual(values = c(0.5, 1))
However, differentiating by alpha is a little awkward. You could instead map to fill and use light and dark purples:
ggplot(df, aes(x = resp, fill = as.factor(expl))) +
geom_histogram(bins = 10) +
scale_fill_manual(values = c("0" = "mediumpurple1", "1" = "mediumpurple4"))
Note also that you can adjust the position of the histogram bars if you need to, by assigning geom_histogram(position = ...), where you could fill in with something such as "dodge" if that's what you'd like.
If you want a legend on the alpha value, the idea is to include it as an aesthetic rather than as a direct argument as you tried. In order to do this, a simple solution is to enrich the data frame used by ggplot:
df2 <- rbind(
cbind(df, filter="all lines"),
cbind(subset(df, expl == '1'), filter="expl==1")
)
df2 corresponds to df after appending the lines from your subset of interest (with a field filter telling from which copy each record comes)
Then, this solves your problem
ggplot(df2, aes(resp, alpha=filter)) +
geom_histogram(fill="#BEBADA", bins=10, position="identity") +
scale_alpha_discrete(range=c(.5,1))
I am trying to generate a (grouped) density plot labelled with sample sizes.
Sample data:
set.seed(100)
df <- data.frame(ab.class = c(rep("A", 200), rep("B", 200)),
val = c(rnorm(200, 0, 1), rnorm(200, 1, 1)))
The unlabelled density plot is generated and looks as follows:
ggplot(df, aes(x = val, group = ab.class)) +
geom_density(aes(fill = ab.class), alpha = 0.4)
What I want to do is add text labels somewhere near the peak of each density, showing the number of samples in each group. However, I cannot find the right combination of options to summarise the data in this way.
I tried to adapt the code suggested in this answer to a similar question on boxplots: https://stackoverflow.com/a/15720769/1836013
n_fun <- function(x){
return(data.frame(y = max(x), label = paste0("n = ",length(x))))
}
ggplot(df, aes(x = val, group = ab.class)) +
geom_density(aes(fill = ab.class), alpha = 0.4) +
stat_summary(geom = "text", fun.data = n_fun)
However, this fails with Error: stat_summary requires the following missing aesthetics: y.
I also tried adding y = ..density.. within aes() for each of the geom_density() and stat_summary() layers, and in the ggplot() object itself... none of which solved the problem.
I know this could be achieved by manually adding labels for each group, but I was hoping for a solution that generalises, and e.g. allows the label colour to be set via aes() to match the densities.
Where am I going wrong?
The y in the return of fun.data is not the aes. stat_summary complains that he cannot find y, which should be specificed in global settings at ggplot(df, aes(x = val, group = ab.class, y = or stat_summary(aes(y = if global setting of y is not available. The fun.data compute where to display point/text/... at each x based on y given in the data through aes. (I am not sure whether I have made this clear. Not a native English speaker).
Even if you have specified y through aes, you won't get desired results because stat_summary compute a y at each x.
However, you can add text to desired positions by geom_text or annotate:
# save the plot as p
p <- ggplot(df, aes(x = val, group = ab.class)) +
geom_density(aes(fill = ab.class), alpha = 0.4)
# build the data displayed on the plot.
p.data <- ggplot_build(p)$data[[1]]
# Note that column 'scaled' is used for plotting
# so we extract the max density row for each group
p.text <- lapply(split(p.data, f = p.data$group), function(df){
df[which.max(df$scaled), ]
})
p.text <- do.call(rbind, p.text) # we can also get p.text with dplyr.
# now add the text layer to the plot
p + annotate('text', x = p.text$x, y = p.text$y,
label = sprintf('n = %d', p.text$n), vjust = 0)
I have a data.frame that looks something like this:
HSP90AA1 SSH2 ACTB TotalTranscripts
ESC_11_TTCGCCAAATCC 8.053308 12.038484 10.557234 33367.23
ESC_10_TTGAGCTGCACT 9.430003 10.687959 10.437068 30285.41
ESC_11_GCCGCGTTATAA 7.953726 9.918988 10.078192 30133.94
ESC_11_GCATTCTGGCTC 11.184402 11.056144 8.316846 24857.07
ESC_11_GTTACATTTCAC 11.943733 11.004500 9.240883 23629.00
ESC_11_CCGTTGCCCCTC 7.441695 9.774733 7.566619 22792.18
The TotalTranscripts column is sorted in descending order. What I'd like to do is generate three bar graphs using ggplot2 with each bar graph corresponding to each column of the data.frame with the exception of TotalTranscripts. I'd like the bar graphs to be ordered by TotalTranscripts just as the data.frame. I would be ideal to have these bar graphs on one plot using a facet wrap.
Any help would be greatly appreciated! Thank you!
EDIT: Here is my current code using barplot().
cells = "ESC"
genes = c("HSP90AA1", "SSH2", "ACTB")
g = data[genes,grep(cells, colnames(data))]
g = data.frame(t(g), colSums(data)[grep(cells, colnames(data))])
colnames(g)[ncol(g)] = "TotalTranscripts"
g = g[order(g$TotalTranscripts, decreasing=T), , drop=F]
barplot(as.matrix(g[1]), beside=TRUE, names.arg=paste(rownames(g)," (",g$TotalTranscripts,")",sep=""), las=2, col="light blue", cex.names=0.3, main=paste(colnames(g)[1], "\nCells sorted by total number of transcripts (colSums)", sep=""))
This will generate a plot that looks like this.
Again, the problem I seem to be having here is how to have multiple of these plots on the same image. I would like to add 20+ columns to this data.frame but I've cut this down to 3 for the sake of simplicity.
EDIT: Current code incorporating the answer below
cells = "ESC"
genes = rownames(data[x,])[1:8]
# genes = c("HSP90AA1", "SSH2", "ACTB")
g = data[genes,grep(cells, colnames(data))]
g = data.frame(t(g), colSums(data)[grep(cells, colnames(data))])
colnames(g)[ncol(g)] = "TotalTranscripts"
g = g[order(g$TotalTranscripts, decreasing=T), , drop=F]
g$rowz <- row.names(g)
g$Cells <- reorder(g$rowz, rev(g$TotalTranscripts))
df1 <- melt(g, id.vars = c("Cells", "TotalTranscripts"), measure.vars=genes)
ggplot(df1, aes(x = Cells, y = value)) + geom_bar(stat = "identity") +
theme(axis.title.x=element_blank(), axis.text.x = element_blank()) +
facet_wrap(~ variable, scales = "free") +
theme_bw() + theme(axis.text.x = element_text(angle = 90))
Here is the example data for anybody else:
df <- structure(list(HSP90AA1 = c(8.053308, 9.430003, 7.953726, 11.184402,
11.943733, 7.441695), SSH2 = c(12.038484, 10.687959, 9.918988,
11.056144, 11.0045, 9.774733), ACTB = c(10.557234, 10.437068,
10.078192, 8.316846, 9.240883, 7.566619), TotalTranscripts = c(33367.23,
30285.41, 30133.94, 24857.07, 23629, 22792.18)), .Names = c("HSP90AA1",
"SSH2", "ACTB", "TotalTranscripts"), class = "data.frame", row.names = c("ESC_11_TTCGCCAAATCC",
"ESC_10_TTGAGCTGCACT", "ESC_11_GCCGCGTTATAA", "ESC_11_GCATTCTGGCTC",
"ESC_11_GTTACATTTCAC", "ESC_11_CCGTTGCCCCTC"))
And here is a solution:
#New column for row names so they can be used as x-axis elements
df$rowz <- row.names(df)
#Explicitly order the rows (see the Kohske link)
df$rowz1 <- reorder(df$rowz, rev(df$TotalTranscripts))
library(reshape2)
#Melt the data from wide to long
df1 <- melt(df, id.vars = c("rowz1", "TotalTranscripts"),
measure.vars = c("HSP90AA1", "SSH2", "ACTB"))
library(ggplot2)
gp <- ggplot(df1, aes(x = rowz1, y = value)) + geom_bar(stat = "identity") +
facet_wrap(~ variable, scales = "free") +
theme_bw()
gp + theme(axis.text.x = element_text(angle = 90))
This example by Kohske is a constant reference for me on ordering elements in ggplot2.
If you have many columns, but the same six ESC complexes, you can switch the groupings, i.e. x = variable and facet_wrap(~ rowz1), but this fundamentally changes how you are visualizing/comparing your data. Also, consider facet_grid(row ~ column) if you can organize the columns by 2 components (Columns being the data that are melted into 'variable' and 'value').
And this additional SO solution isn't related to your question, but it is an elegant way to reorder elements in each facet by their values (for future reference).
Finally, the method that will give you the finest control is to plot each graph separately and combine the grobs. Baptiste's packages like gridExtra and gtable are useful for these tasks.
**EDIT in response to new information from OP**
The OP has subsequently asked how to visualize the data, especially when there are more ESC categorical variables (up to 600+).
Here are some examples, with the big caveat that with many categorical variables, they should be grouped or converted to a continuous variable somehow.
#Plot colour to a few discrete, categorical variables
gp + aes(fill = rowz1) +
theme(axis.text.x = element_blank(), axis.ticks.x = element_blank()) +
labs(x = NULL, fill = "Cell", title = "Discrete categorical variables")
#Plot colour on a continuous scale.
#Ultimately, not appropriate for this example! (but shown for reference)
#More appropriate: fill = TotalTranscripts
gp + aes(fill = as.numeric(rowz1)) +
theme(axis.text.x = element_blank(), axis.ticks.x = element_blank()) +
labs(x = NULL, title = "Continuous variables (legend won't work for many values)") +
scale_fill_gradient2(name = "Cell",
breaks = as.numeric(df1$rowz1),
labels = df1$rowz1,
midpoint=median(as.numeric(df1$rowz1)))
#x is continuous, colour plotted to the categorical variable.
#Same caveats as earlier.
gp1 <- ggplot(df1, aes(x = TotalTranscripts/1000, y = value, colour = rowz1)) +
geom_point(size=3) + facet_wrap(~ variable, scales = "free") +
labs(title = "X is an actual continuous variable") +
theme_bw() + labs(x = bquote("Total Transcripts,"~10^3), colour = "Cell")
gp1
So, I have a fairly large dataset (Dropbox: csv file) that I'm trying to plot using geom_boxplot. The following produces what appears to be a reasonable plot:
require(reshape2)
require(ggplot2)
require(scales)
require(grid)
require(gridExtra)
df <- read.csv("\\Downloads\\boxplot.csv", na.strings = "*")
df$year <- factor(df$year, levels = c(2010,2011,2012,2013,2014), labels = c(2010,2011,2012,2013,2014))
d <- ggplot(data = df, aes(x = year, y = value)) +
geom_boxplot(aes(fill = station)) +
facet_grid(station~.) +
scale_y_continuous(limits = c(0, 15)) +
theme(legend.position = "none"))
d
However, when you dig a little deeper, problems creep in that freak me out. When I labeled the boxplot medians with their values, the following plot results.
df.m <- aggregate(value~year+station, data = df, FUN = function(x) median(x))
d <- d + geom_text(data = df.m, aes(x = year, y = value, label = value))
d
The medians plotted by geom_boxplot aren't at the medians at all. The labels are plotted at the correct y-axis value, but the middle hinge of the boxplots are definitely not at the medians. I've been stumped by this for a few days now.
What is the reason for this? How can this type of display be produced with correct medians? How can this plot be debugged or diagnosed?
The solution to this question is in the application of scale_y_continuous. ggplot2 will perform operations in the following order:
Scale Transformations
Statistical Computations
Coordinate Transformations
In this case, because a scale transformation is invoked, ggplot2 excludes data outside the scale limits for the statistical computation of the boxplot hinges. The medians calculated by the aggregate function and used in the geom_text instruction will use the entire dataset, however. This can result in different median hinges and text labels.
The solution is to omit the scale_y_continuous instruction and instead use:
d <- ggplot(data = df, aes(x = year, y = value)) +
geom_boxplot(aes(fill = station)) +
facet_grid(station~.) +
theme(legend.position = "none")) +
coord_cartesian(y = c(0,15))
This allows ggplot2 to calculate the boxplot hinge stats using the entire dataset, while limiting the plot size of the figure.