I'm trying to create boxplots with descriptive information (mean, count, etc.).
I found a lot of examples of how to add the numbers for one boxplot with different groups, but I didn't found a way to add those numbers for multiple boxplots grid (facet_wrap).
for example, this article describes how to add numbers for one boxplot - I'm trying to do the same for multiple boxplots
library(reshape2)
library(ggplot2)
df.m <- melt(iris, id.var = "Species")
p <- ggplot(data = df.m, aes(x=variable, y=value)) +
geom_boxplot(aes(fill=Species))
p + facet_wrap( ~ variable, scales="free")
and on top of this plot - I want to add the relevant descriptive information on top of each box.
Create the function that makes counts and means
stat_box_data <- function(y) {
return(
data.frame(
y = 0.5+1.1*max(y), #may need to modify this depending on your data
label = paste('count =', length(y), '\n',
'mean =', round(mean(y), 1), '\n')
)
)
}
)
}
df.m <- melt(iris, id.var = "Species")
You may want to use this or something similar if you have large outliers instead of the y=0.5... bit above:
y=quantile(y,probs=0.95)*1.1,
Plot the data and use stat_summary with your custom function
ggplot(data = df.m, aes(x=Species, y=value)) +
geom_boxplot(aes(fill=Species))+
stat_summary(
fun.data = stat_box_data,
geom = "text",
hjust = 0.5,
vjust = 0.9
) +
facet_wrap( ~ variable, scales="free")
Related
I know how to modify titles in ggplot without altering the original data. Suppose I have the following data frame and I want to change the labels. Then, I would do so in the following way
df <- data.frame(x = 1:4, y = 1:4, label = c(c("params[1]", "params[2]", "params[3]",
"params[4]")))
params_names <- list(
'params[1]'= "beta[11]",
'params[2]'= "beta[22]",
'params[3]'= "beta[33]",
'params[4]'= "beta[44]"
)
param_labeller <- function(variable, value){
params_names[value]
}
ggplot(df, aes(x=x,y=y)) +
geom_point() +
facet_grid(~label, labeller = param_labeller)
If I wanted to display the subscripts, I would just do this
ggplot(df, aes(x=x,y=y)) +
geom_point() +
facet_grid(~label, labeller = label_parsed)
How do I apply both operations at the same time?
I don't know exactly if this conflicts with you not wanting to "alter" the original data, but you add the labelling information to the factor itself:
df$label2 <- factor(df$label,
labels = c("beta[4]", "beta[24]", "beta[42]", "beta[43]"))
ggplot(df, aes(x = x, y = y)) +
geom_point() +
facet_grid( ~ label2, labeller = label_parsed)
This produces the following plot:
Plot with formatted facet labels
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'
)
How do I show the specific values of variables on a graph?
For example:
ggplot(data=df)+
geom_bar(mapping=aes(x=var))
How do I get it to have the actual count on the bar chart?
I believe this question has asked before but I couldn' find a duplicate quickly.
Here is an example how to annotate the columns of a bar chart with the counts:
n_row <- 100L
set.seed(123L)
df <- data.frame(var = sample(LETTERS[1:5], n_row, TRUE, 5:1))
library(ggplot2)
ggplot(data = df) + aes(x = var) +
geom_bar() +
stat_count(geom = "text", aes(label = ..count..), vjust = "bottom")
Alternatively, we can write
ggplot(data = df) + aes(x = var, label = ..count..) +
geom_bar() +
geom_text(stat = "count", vjust = "bottom")
Some geoms and stats do compute variables which can be accessed using special names like ..count... To plot labels, the x and y positions and the text need to be specified. The x position is taken from the date as specified in aes(). The y position seems to be taken automatically from the statistical transformation but the text needs to be specified explicitely.
Suggested reading:
Statistical transformations in R for Data Science
ggplot2 homepage
I asked a question yesterday about annotating the x-axis with N in a faceted plot using a minimal example that turns out to be too simple, relative to my real problem. The answer given there works in the case of complete data, but if you have missing facets you would like to preserve, the combination of facet_wrap options drop=FALSE and scales="free_x" triggers an error: "Error in if (zero_range(from) || zero_range(to)) { : missing value where TRUE/FALSE needed"
Here is a new, less-minimal example. The goal here is to produce a large graph with two panels using grid.arrange; the first showing absolute values over time by treatment group; the second showing the change from baseline over time by treatment group. In the second panel, we need a blank facet when vis=1.
# setup
library(ggplot2)
library(plyr)
library(gridExtra)
trt <- factor(rep(LETTERS[1:2],150),ordered=TRUE)
vis <- factor(c(rep(1,150),rep(2,100),rep(3,50)),ordered=TRUE)
id <- c(c(1:150),c(1:100),c(1:50))
val <- rnorm(300)
data <- data.frame(id,trt,vis,val)
base <- with(subset(data,vis==1),data.frame(id,trt,baseval=val))
data <- merge(data,base,by="id")
data <- transform(data,chg=ifelse(vis==1,NA,val-baseval))
data.sum <- ddply(data, .(vis, trt), summarise, N=length(na.omit(val)))
data <- merge(data,data.sum)
data <- transform(data, trtN=paste(trt,N,sep="\n"))
mytheme <- theme_bw() + theme(panel.margin = unit(0, "lines"), strip.background = element_blank())
# no missing facets
plot.a <- ggplot(data) + geom_boxplot(aes(x=trtN,y=val,group=trt,colour=trt), show.legend=FALSE) +
facet_wrap(~ vis, drop=FALSE, switch="x", nrow=1, scales="free_x") +
labs(x="Visit") + mytheme
# first facet should be blank
plot.b <- ggplot(data) + geom_boxplot(aes(x=trtN,y=chg,group=trt,colour=trt), show.legend=FALSE) +
facet_wrap(~ vis, drop=FALSE, switch="x", nrow=1, scales="free_x") +
labs(x="Visit") + mytheme
grid.arrange(plot.a,plot.b,nrow=2)
You can add a blank layer to draw all the facets in your second plot. The key is that you need a variable that exists for every level of vis to use as your y variable. In your case you can simply use the variable you used in your first plot.
ggplot(data) +
geom_boxplot(aes(x = trtN, y = chg, group = trt, colour = trt), show.legend = FALSE) +
geom_blank(aes(x = trtN, y = val)) +
facet_wrap(~ vis, switch = "x", nrow = 1, scales = "free_x") +
labs(x="Visit") + mytheme
If your variables have different ranges, you can set the y limits using the overall min and max of your boxplot y variable.
+ scale_y_continuous(limits = c(min(data$chg, na.rm = TRUE), max(data$chg, na.rm = TRUE)))
I have data where I look at the difference in growth between a monoculture and a mixed culture for two different species. Additionally, I made a graph to make my data clear.
I want a barplot with error bars, the whole dataset is of course bigger, but for this graph this is the data.frame with the means for the barplot.
plant species means
Mixed culture Elytrigia 0.886625
Monoculture Elytrigia 1.022667
Monoculture Festuca 0.314375
Mixed culture Festuca 0.078125
With this data I made a graph in ggplot2, where plant is on the x-axis and means on the y-axis, and I used a facet to divide the species.
This is my code:
limits <- aes(ymax = meansS$means + eS$se, ymin=meansS$means - eS$se)
dodge <- position_dodge(width=0.9)
myplot <- ggplot(data=meansS, aes(x=plant, y=means, fill=plant)) + facet_grid(. ~ species)
myplot <- myplot + geom_bar(position=dodge) + geom_errorbar(limits, position=dodge, width=0.25)
myplot <- myplot + scale_fill_manual(values=c("#6495ED","#FF7F50"))
myplot <- myplot + labs(x = "Plant treatment", y = "Shoot biomass (gr)")
myplot <- myplot + opts(title="Plant competition")
myplot <- myplot + opts(legend.position = "none")
myplot <- myplot + opts(panel.grid.minor=theme_blank(), panel.grid.major=theme_blank())
So far it is fine. However, I want to add two different horizontal lines in the two facets. For that, I used this code:
hline.data <- data.frame(z = c(0.511,0.157), species = c("Elytrigia","Festuca"))
myplot <- myplot + geom_hline(aes(yintercept = z), hline.data)
However if I do that, I get a plot were there are two extra facets, where the two horizontal lines are plotted. Instead, I want the horizontal lines to be plotted in the facets with the bars, not to make two new facets. Anyone a idea how to solve this.
I think it makes it clearer if I put the graph I create now:
Make sure that the variable species is identical in both datasets. If it a factor in one on them, then it must be a factor in the other too
library(ggplot2)
dummy1 <- expand.grid(X = factor(c("A", "B")), Y = rnorm(10))
dummy1$D <- rnorm(nrow(dummy1))
dummy2 <- data.frame(X = c("A", "B"), Z = c(1, 0))
ggplot(dummy1, aes(x = D, y = Y)) + geom_point() + facet_grid(~X) +
geom_hline(data = dummy2, aes(yintercept = Z))
dummy2$X <- factor(dummy2$X)
ggplot(dummy1, aes(x = D, y = Y)) + geom_point() + facet_grid(~X) +
geom_hline(data = dummy2, aes(yintercept = Z))