geom_histogram and data labels [duplicate] - r

Below code works well and it labels the barplot correctly, However, if I try geom_text for a histogram I fail since geom_text requires a y-component and a histogram's y component is not part of the original data.
Label an "ordinary" bar plot (geom_bar(stat = "identity") works well:
ggplot(csub, aes(x = Year, y = Anomaly10y, fill = pos)) +
geom_bar(stat = "identity", position = "identity") +
geom_text(aes(label = Anomaly10y,vjust=1.5))
My Problem: How to get the correct y and label (indicated by ?) for geom_text, to put labels on top of the histogram bars
ggplot(csub,aes(x = Anomaly10y)) +
geom_histogram()
geom_text(aes(label = ?, vjust = 1.5))
geom_text requires x, y and labels. However, y and labels are not in the original data, but generated by the geom_histogram function. How can I extract the necessary data to position labels on a histogram?

geom_histogram() is just a fancy wrapper to stat_bin so you can all that yourself with the bars and text that you like. Here's an example
#sample data
set.seed(15)
csub<-data.frame(Anomaly10y = rpois(50,5))
And then we plot it with
ggplot(csub,aes(x=Anomaly10y)) +
stat_bin(binwidth=1) + ylim(c(0, 12)) +
stat_bin(binwidth=1, geom="text", aes(label=..count..), vjust=-1.5)
to get

Ok to make it aesthetically appealing here is the solution:
set.seed(15)
csub <- data.frame(Anomaly10y = rpois(50, 5))
Now Plot it
csub %>%
ggplot(aes(Anomaly10y)) +
geom_histogram(binwidth=1) +
stat_bin(binwidth=1, geom='text', color='white', aes(label=..count..),
position=position_stack(vjust = 0.5))
resultant plot will be

Related

How to flip a geom_area to be under the line when using scale_y_reverse()

I had to flip the axis of my line, but still need the geom_area to be under the curve. However I cannot figure out how to do so.
This is the line of code I tried
ggplot(PalmBeachWell, aes(x=Date, y=Depth.to.Water.Below.Land.Surface.in.ft.)) +
geom_area(position= "identity", fill='lightblue') +
theme_classic() +
geom_line(color="blue") +
scale_y_reverse()
and here is what i got
One option would be to use a geom_ribbon to fill the area above the curve which after applying scale_y_reverse will result in a fill under the curve.
Using some fake example data based on the ggplot2::economics dataset:
library(ggplot2)
PalmBeachWell <- economics[c("date", "psavert")]
names(PalmBeachWell) <- c("Date", "Depth.to.Water.Below.Land.Surface.in.ft.")
ggplot(PalmBeachWell, aes(x = Date, y = Depth.to.Water.Below.Land.Surface.in.ft.)) +
geom_ribbon(aes(ymin = Depth.to.Water.Below.Land.Surface.in.ft., ymax = Inf),
fill = "lightblue"
) +
geom_line(color = "blue") +
scale_y_reverse() +
theme_classic()

ggplot2 coord_flip() with geom_text

I'm trying to find a way to easily flip a plot annotated with geom_text(). The problem is that if I use coord_flip(), the labels are kind of not flipped.
A simple example, if I flip the plot like that:
df <- count(diamonds, cut)
ggplot(df, aes(x = cut, y = n, label = n)) +
geom_bar(stat = "identity") +
geom_text()
by adding coord_flip(), I'm getting:
I know that this could be a desired behaviour in some cases but instead of that, I need the labels on the bars to stay aligned with the bars and look more like:
Is there any solution to that?
You can use the angle aesthetic in geom_text, setting it to a fixed value.
ggplot(df, aes(x = cut, y = n, label = n)) +
geom_bar(stat = "identity") +
geom_text(angle = 270) +
coord_flip()

R ggplot2 - displaying values inside a histogram bar [duplicate]

Using ggplot2 1.0.0, I followed the instructions in below post to figure out how to plot percentage bar plots across factors:
Sum percentages for each facet - respect "fill"
test <- data.frame(
test1 = sample(letters[1:2], 100, replace = TRUE),
test2 = sample(letters[3:8], 100, replace = TRUE)
)
library(ggplot2)
library(scales)
ggplot(test, aes(x= test2, group = test1)) +
geom_bar(aes(y = ..density.., fill = factor(..x..))) +
facet_grid(~test1) +
scale_y_continuous(labels=percent)
However, I cannot seem to get a label for either the total count or the percentage above each of the bar plots when using geom_text.
What is the correct addition to the above code that also preserves the percentage y-axis?
Staying within ggplot, you might try
ggplot(test, aes(x= test2, group=test1)) +
geom_bar(aes(y = ..density.., fill = factor(..x..))) +
geom_text(aes( label = format(100*..density.., digits=2, drop0trailing=TRUE),
y= ..density.. ), stat= "bin", vjust = -.5) +
facet_grid(~test1) +
scale_y_continuous(labels=percent)
For counts, change ..density.. to ..count.. in geom_bar and geom_text
UPDATE for ggplot 2.x
ggplot2 2.0 made many changes to ggplot including one that broke the original version of this code when it changed the default stat function used by geom_bar ggplot 2.0.0. Instead of calling stat_bin, as before, to bin the data, it now calls stat_count to count observations at each location. stat_count returns prop as the proportion of the counts at that location rather than density.
The code below has been modified to work with this new release of ggplot2. I've included two versions, both of which show the height of the bars as a percentage of counts. The first displays the proportion of the count above the bar as a percent while the second shows the count above the bar. I've also added labels for the y axis and legend.
library(ggplot2)
library(scales)
#
# Displays bar heights as percents with percentages above bars
#
ggplot(test, aes(x= test2, group=test1)) +
geom_bar(aes(y = ..prop.., fill = factor(..x..)), stat="count") +
geom_text(aes( label = scales::percent(..prop..),
y= ..prop.. ), stat= "count", vjust = -.5) +
labs(y = "Percent", fill="test2") +
facet_grid(~test1) +
scale_y_continuous(labels=percent)
#
# Displays bar heights as percents with counts above bars
#
ggplot(test, aes(x= test2, group=test1)) +
geom_bar(aes(y = ..prop.., fill = factor(..x..)), stat="count") +
geom_text(aes(label = ..count.., y= ..prop..), stat= "count", vjust = -.5) +
labs(y = "Percent", fill="test2") +
facet_grid(~test1) +
scale_y_continuous(labels=percent)
The plot from the first version is shown below.
This is easier to do if you pre-summarize your data. For example:
library(ggplot2)
library(scales)
library(dplyr)
set.seed(25)
test <- data.frame(
test1 = sample(letters[1:2], 100, replace = TRUE),
test2 = sample(letters[3:8], 100, replace = TRUE)
)
# Summarize to get counts and percentages
test.pct = test %>% group_by(test1, test2) %>%
summarise(count=n()) %>%
mutate(pct=count/sum(count))
ggplot(test.pct, aes(x=test2, y=pct, colour=test2, fill=test2)) +
geom_bar(stat="identity") +
facet_grid(. ~ test1) +
scale_y_continuous(labels=percent, limits=c(0,0.27)) +
geom_text(data=test.pct, aes(label=paste0(round(pct*100,1),"%"),
y=pct+0.012), size=4)
(FYI, you can put the labels inside the bar as well, for example, by changing the last line of code to this: y=pct*0.5), size=4, colour="white"))
I've used all of your code and came up with this. First assign your ggplot to a variable i.e. p <- ggplot(...) + geom_bar(...) etc. Then you could do this. You don't need to summarize much since ggplot has a build function that gives you all of this already. I'll leave it to you for the formatting and such. Good luck.
dat <- ggplot_build(p)$data %>% ldply() %>% select(group,density) %>%
do(data.frame(xval = rep(1:6, times = 2),test1 = mapvalues(.$group, from = c(1,2), to = c("a","b")), density = .$density))
p + geom_text(data=dat, aes(x = xval, y = (density + .02), label = percent(density)), colour="black", size = 3)

How to add percentage or count labels above percentage bar plot?

Using ggplot2 1.0.0, I followed the instructions in below post to figure out how to plot percentage bar plots across factors:
Sum percentages for each facet - respect "fill"
test <- data.frame(
test1 = sample(letters[1:2], 100, replace = TRUE),
test2 = sample(letters[3:8], 100, replace = TRUE)
)
library(ggplot2)
library(scales)
ggplot(test, aes(x= test2, group = test1)) +
geom_bar(aes(y = ..density.., fill = factor(..x..))) +
facet_grid(~test1) +
scale_y_continuous(labels=percent)
However, I cannot seem to get a label for either the total count or the percentage above each of the bar plots when using geom_text.
What is the correct addition to the above code that also preserves the percentage y-axis?
Staying within ggplot, you might try
ggplot(test, aes(x= test2, group=test1)) +
geom_bar(aes(y = ..density.., fill = factor(..x..))) +
geom_text(aes( label = format(100*..density.., digits=2, drop0trailing=TRUE),
y= ..density.. ), stat= "bin", vjust = -.5) +
facet_grid(~test1) +
scale_y_continuous(labels=percent)
For counts, change ..density.. to ..count.. in geom_bar and geom_text
UPDATE for ggplot 2.x
ggplot2 2.0 made many changes to ggplot including one that broke the original version of this code when it changed the default stat function used by geom_bar ggplot 2.0.0. Instead of calling stat_bin, as before, to bin the data, it now calls stat_count to count observations at each location. stat_count returns prop as the proportion of the counts at that location rather than density.
The code below has been modified to work with this new release of ggplot2. I've included two versions, both of which show the height of the bars as a percentage of counts. The first displays the proportion of the count above the bar as a percent while the second shows the count above the bar. I've also added labels for the y axis and legend.
library(ggplot2)
library(scales)
#
# Displays bar heights as percents with percentages above bars
#
ggplot(test, aes(x= test2, group=test1)) +
geom_bar(aes(y = ..prop.., fill = factor(..x..)), stat="count") +
geom_text(aes( label = scales::percent(..prop..),
y= ..prop.. ), stat= "count", vjust = -.5) +
labs(y = "Percent", fill="test2") +
facet_grid(~test1) +
scale_y_continuous(labels=percent)
#
# Displays bar heights as percents with counts above bars
#
ggplot(test, aes(x= test2, group=test1)) +
geom_bar(aes(y = ..prop.., fill = factor(..x..)), stat="count") +
geom_text(aes(label = ..count.., y= ..prop..), stat= "count", vjust = -.5) +
labs(y = "Percent", fill="test2") +
facet_grid(~test1) +
scale_y_continuous(labels=percent)
The plot from the first version is shown below.
This is easier to do if you pre-summarize your data. For example:
library(ggplot2)
library(scales)
library(dplyr)
set.seed(25)
test <- data.frame(
test1 = sample(letters[1:2], 100, replace = TRUE),
test2 = sample(letters[3:8], 100, replace = TRUE)
)
# Summarize to get counts and percentages
test.pct = test %>% group_by(test1, test2) %>%
summarise(count=n()) %>%
mutate(pct=count/sum(count))
ggplot(test.pct, aes(x=test2, y=pct, colour=test2, fill=test2)) +
geom_bar(stat="identity") +
facet_grid(. ~ test1) +
scale_y_continuous(labels=percent, limits=c(0,0.27)) +
geom_text(data=test.pct, aes(label=paste0(round(pct*100,1),"%"),
y=pct+0.012), size=4)
(FYI, you can put the labels inside the bar as well, for example, by changing the last line of code to this: y=pct*0.5), size=4, colour="white"))
I've used all of your code and came up with this. First assign your ggplot to a variable i.e. p <- ggplot(...) + geom_bar(...) etc. Then you could do this. You don't need to summarize much since ggplot has a build function that gives you all of this already. I'll leave it to you for the formatting and such. Good luck.
dat <- ggplot_build(p)$data %>% ldply() %>% select(group,density) %>%
do(data.frame(xval = rep(1:6, times = 2),test1 = mapvalues(.$group, from = c(1,2), to = c("a","b")), density = .$density))
p + geom_text(data=dat, aes(x = xval, y = (density + .02), label = percent(density)), colour="black", size = 3)

Get values and positions to label a ggplot histogram

Below code works well and it labels the barplot correctly, However, if I try geom_text for a histogram I fail since geom_text requires a y-component and a histogram's y component is not part of the original data.
Label an "ordinary" bar plot (geom_bar(stat = "identity") works well:
ggplot(csub, aes(x = Year, y = Anomaly10y, fill = pos)) +
geom_bar(stat = "identity", position = "identity") +
geom_text(aes(label = Anomaly10y,vjust=1.5))
My Problem: How to get the correct y and label (indicated by ?) for geom_text, to put labels on top of the histogram bars
ggplot(csub,aes(x = Anomaly10y)) +
geom_histogram()
geom_text(aes(label = ?, vjust = 1.5))
geom_text requires x, y and labels. However, y and labels are not in the original data, but generated by the geom_histogram function. How can I extract the necessary data to position labels on a histogram?
geom_histogram() is just a fancy wrapper to stat_bin so you can all that yourself with the bars and text that you like. Here's an example
#sample data
set.seed(15)
csub<-data.frame(Anomaly10y = rpois(50,5))
And then we plot it with
ggplot(csub,aes(x=Anomaly10y)) +
stat_bin(binwidth=1) + ylim(c(0, 12)) +
stat_bin(binwidth=1, geom="text", aes(label=..count..), vjust=-1.5)
to get
Ok to make it aesthetically appealing here is the solution:
set.seed(15)
csub <- data.frame(Anomaly10y = rpois(50, 5))
Now Plot it
csub %>%
ggplot(aes(Anomaly10y)) +
geom_histogram(binwidth=1) +
stat_bin(binwidth=1, geom='text', color='white', aes(label=..count..),
position=position_stack(vjust = 0.5))
resultant plot will be

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