More bullseye plotting in R - r

I'm using ggplot2 to make some bullseye charts in R. They look delightful, and everyone is very pleased - except that they'd like to have the values of the bullseye layers plotted on the chart. I'd be happy just to put them in the lower-right corner of the plot, or even in the plot margins, but I'm having some difficulty doing this.
Here's the example data again:
critters <- structure(list(Zoo = "Omaha", Animals = 50, Bears = 10, PolarBears = 3), .Names = c("Zoo",
"Animals", "Bears", "PolarBears"), row.names = c(NA, -1L), class = "data.frame")
And how to plot it:
d <- data.frame(animal=factor(c(rep("Animals", critters$Animals),
rep("Bears", critters$Bears), rep("PolarBears", critters$PolarBears)),
levels = c("PolarBears", "Bears", "Animals"), ordered= TRUE))
grr <- ggplot(d, aes(x = factor(1), fill = factor(animal))) + geom_bar() +
coord_polar() + labs(x = NULL, fill = NULL) +
scale_fill_manual(values = c("firebrick2", "yellow2", "green3")) +
opts(title = paste("Animals, Bears and Polar Bears:\nOmaha Zoo", sep=""))
I'd like to add a list to, say, the lower right corner of this plot saying,
Animals: 50
Bears: 10
PolarBears: 3
But I can't figure out how. My efforts so far with annotate() have been thwarted, in part by the polar coordinates. If I have to add the numbers to the title, so be it - but I always hold out hope for a more elegant solution.
EDIT:
An important note for those who come after: the bullseye is a bar plot mapped to polar coordinates. The ggplot2 default for bar plots is, sensibly, to stack them. However, that means that the rings of your bullseye will also be stacked (e.g. the radius in my example equals the sum of all three groups, 63, instead of the size of the largest group, 50). I don't think that's what most people expect from a bullseye plot, especially when the groups are nested. Using geom_bar(position = position_identity()) will turn the stacked rings into layered circles.
EDIT 2: Example from ggplot2 docs:

you can also add it directly to the plot:
grr <- ggplot(d, aes(x = factor(1), fill = factor(animal))) + geom_bar() +
coord_polar() + labs(x = NULL, fill = NULL) +
scale_fill_manual(values = c("firebrick2", "yellow2", "green3")) +
opts(title = paste("Animals, Bears and Polar Bears:\nOmaha Zoo", sep=""))+
geom_text(y=c(3,10,50)-3,label=c("3","10","50"),size=4)
grr

You could add the numbers to the legend.
library(ggplot2)
critters <- structure(list(Zoo = "Omaha", Animals = 50, Bears = 10, PolarBears = 3), .Names = c("Zoo", "Animals", "Bears", "PolarBears"), row.names = c(NA, -1L), class = "data.frame")
d <- data.frame(animal=factor(c(rep("Animals", critters$Animals),
rep("Bears", critters$Bears), rep("PolarBears", critters$PolarBears)),
levels = c("PolarBears", "Bears", "Animals"), ordered= TRUE))
levels(d$animal) <- apply(data.frame(table(d$animal)), 1, paste, collapse = ": ")
ggplot(d, aes(x = factor(1), fill = factor(animal))) + geom_bar() +
coord_polar() + labs(x = NULL, fill = NULL) +
scale_fill_manual(values = c("firebrick2", "yellow2", "green3")) +
opts(title = paste("Animals, Bears and Polar Bears:\nOmaha Zoo", sep=""))

Related

plotly overrules ggplot2's scale_fill_manual's labels

I have a sample data set containing a end of week date and a churn value, either be negative or positive. In ggplot2 I use the scale_fill_manual() on the sign of the value as group.
This works perfectly fine showing the colors for positive versus negative values. Also the labels get rewritten according to the labels provided. However if I simply make it a plotly graph I lose my labels and they are set back to the -1, 1 factors instead. Does plotly not support this and if so is their another way to get this done
library(ggplot2)
library(plotly)
dt <- structure(list(date = structure(c(18651L, 18658L, 18665L, 18672L,
18679L, 18686L, 18693L, 18700L, 18707L, 18714L), class = c("IDate",
"Date")), churn = c(-3.27088948787062, -0.582518144525087, -0.125024925224327,
-0.333746898263027, -0.685714285714286, -0.340165549862042, 0.0601176470588235,
-0.119351608461635, -0.0132513279284316, -0.011201854099989)), row.names = c(NA,
-10L), class = c("data.table", "data.frame"))
plot_ggplot <- ggplot(dt, aes(x = date, y = churn * 100)) +
geom_bar(stat = "identity", aes(fill = factor(sign(churn)))) +
scale_fill_manual(
values = c("#4da63f", "#e84e62"),
breaks = c("-1", "1"),
labels = c("Growing base", "Declining base")
) +
ylim(-75, 25) +
labs(
title = "Weekly churn rate",
fill = "Legend"
)
plot_ggplot
plot_ggplotly <- ggplotly(plot_ggplot)
plot_ggplotly
Does this do the trick?
dt$base = ifelse(sign(dt$churn)>0, "Growing base","Declining base")
plot_ggplot <- ggplot(dt, aes(x = date, y = churn * 100)) +
geom_bar(stat = "identity", aes(fill = base)) +
scale_fill_manual(
values = c("#4da63f", "#e84e62"),
) +
ylim(-75, 25) +
labs(
title = "Weekly churn rate",
fill = "Legend"
)
plot_ggplot
plot_ggplotly <- ggplotly(plot_ggplot)
edit: I just read the comment, I think it is what was suggested

Legend for bar chart with horizontal bars

I am using ggplot2 to produce a bar chart and I would like to include my main result as well as a "gold standard" on the same chart. I have tried a couple of methods but I am not able to produce an appropriate legend for the chart.
Method 1
Here I use geom_col() for my main result and geom_errorbar() for my "gold standard". I don't know how to show a simple legend (red = gold standard, blue = score) to match this chart. Additionally, I don't like that the error bar overlaps the axis grid line at 1.00 (instead of meeting it exactly).
chart_A_data <- data_frame(students= c("Alice", "Bob", "Charlie"),
score = c(0.5, 0.7, 0.8),
max_score = c(1, 1 , 1))
chart_A <- ggplot(chart_A_data, aes(x = students, y = score)) +
geom_col(fill = "blue") +
geom_errorbar(aes(ymin = max_score, ymax = max_score),
size = 2, colour = "red") +
ggtitle("Chart A", subtitle = "Use errorbars to show \"gold standard\"")
chart_A
Method 2
Here I create dummy variables and produce a stacked bar chart using geom_bar() and then make the unused dummy variable transparent. I am happy with how precise this method is but I don't know how to remove the unused dummy variable from my legend. Additionally, In this case I need to treat any score of 1.00 as a special case (i.e. set it to 0.99 to make space for the "gold standard").
chart_B_data <- chart_A_data %>%
select(-max_score) %>%
# create dummy variables for stacked bars, note: error if score>0.99
mutate(max_score_line = 0.01) %>%
mutate(blank_fill = 0.99 - score) %>%
gather(stat_level, pct, -students) %>%
# set as factor to control order of stacked bars
mutate(stat_level = factor(stat_level,
levels = c("max_score_line", "blank_fill", "score"),
labels = c("max", "", "score")))
chart_B <- ggplot(data = chart_B_data,
aes(x = students, y = pct, fill = stat_level, alpha = stat_level)) +
geom_bar(stat = "identity", position = "stack") +
scale_fill_manual(values = c("red", "pink", "blue")) +
scale_alpha_manual(values = c(1,0,1)) +
ggtitle("Chart B", subtitle = "Create dummy variables and use stacked bar chart")
chart_B
I don't mind if there is a completely different way I should be approaching this, but I really would like to be able to show a gold standard on my bar chart with a simple concise legend. I will be writing a script to do 50-60 of these charts so I don't want to have too many "special cases" to think about.
In case there's only one max score: This may seem a little hacky (and probably not that beautiful), but it does the job:
ggplot(chart_A_data, aes(x = students, y = score))+
geom_col()+
geom_hline(yintercept = chart_A_data$max_score)
Another one:
ggplot(chart_A_data, aes(x = students,
y = score,
fill = students))+
geom_col()+
geom_segment(aes(x = as.numeric(students)-.15,
xend = as.numeric(students)+.15,
y = max_score,
yend = max_score,
color = students))
Here for the case there are variable maximum scores for each student (you may need to play with the hard-coded 0.15 untill you find something suitable):
Edit after the OP clarified request:
ggplot(chart_A_data, aes(x = students,
y = score))+
geom_col(aes(fill = "blue"))+
geom_segment(aes(x = as.numeric(students)-.25,
xend = as.numeric(students)+.25,
y = max_score,
yend = max_score, color = "red"),
size = 1.7)+
scale_fill_identity(name = "",
guide = "legend",
labels = "Score")+
scale_color_manual(name = "",
values = ("red" = "red"),
labels = "Max Score")
Which produces:

R: placing a text with combination of variables over bars in ggplot

Lets draw a bar chart with ggplot2 from the following data (already in a long format). The values of the variable are then placed in the middle of the bars via geom_text() directive.
stuff.dat<-read.csv(text="continent,stuff,num
America,apples,13
America,bananas,13
Europe,apples,30
Europe,bananas,21
total,apples,43
total,bananas,34")
library(ggplot2)
ggplot(stuff.dat, aes(x=continent, y=num,fill=stuff))+geom_col() +
geom_text(position = position_stack(vjust=0.5),
aes(label=num))
Now it is necessary to add on top of the bars the "Apple-Bananas Index", which is defined as f=apples/bananas - just as manually added in the figure. How to program this in ggplot? How it would be possible to add it to the legend as a separate entry?
I think that the easiest way to achieve this is to prepare the data before you create the plot. I define a function abi() that computes the apple-banana-index from stuff.dat given a continent:
abi <- function(cont) {
with(stuff.dat,
num[continent == cont & stuff == "apples"] / num[continent == cont & stuff == "bananas"]
)
}
And then I create a data frame with all the necessary data:
conts <- levels(stuff.dat$continent)
abi_df <- data.frame(continent = conts,
yf = aggregate(num ~ continent, sum, data = stuff.dat)$num + 5,
abi = round(sapply(conts, abi), 1))
Now, I can add that information to the plot:
library(ggplot2)
ggplot(stuff.dat, aes(x = continent, y = num, fill = stuff)) +
geom_col() +
geom_text(position = position_stack(vjust = 0.5), aes(label = num)) +
geom_text(data = abi_df, aes(y = yf, label = paste0("f = ", abi), fill = NA))
Adding fill = NA to the geom_text() is a bit of a hack and leads to a warning. But if fill is not set, plotting will fail with a message that stuff was not found. I also tried to move fill = stuff from ggplot() to geom_col() but this breaks the y⁻coordinate of the text labels inside the bars. There might be a cleaner solution to this, but I haven't found it yet.
Adding the additional legend is, unfortunately, not trivial, because one cannot easily add text outside the plot area. This actually needs two steps: first one adds text using annotation_custom(). Then, you need to turn clipping off to make the text visible (see, e.g., here). This is a possible solution:
p <- ggplot(stuff.dat, aes(x = continent, y = num, fill = stuff)) +
geom_col() +
geom_text(position = position_stack(vjust = 0.5), aes(label = num)) +
geom_text(data = abi_df, aes(y = yf, label = paste0("f = ", abi), fill = NA)) +
guides(size = guide_legend(title = "f: ABI", override.aes = list(fill = 1))) +
annotation_custom(grob = textGrob("f: ABI\n(Apple-\nBanana-\nIndex",
gp = gpar(cex = .8), just = "left"),
xmin = 3.8, xmax = 3.8, ymin = 17, ymax = 17)
# turn off clipping
library(grid)
gt <- ggplot_gtable(ggplot_build(p))
gt$layout$clip[gt$layout$name == "panel"] <- "off"
grid.draw(gt)

Adding percentage labels on pie chart in R

My data frame looks like
df
Group value
1 Positive 52
2 Negative 239
3 Neutral 9
I would like to make a pie chart of the data frame using ggplot.
pie <- ggplot(df, aes(x="", y=value, fill=Group)) +
geom_bar(width = 1, stat = "identity") +
coord_polar("y", start=0)
This is my pie chart.
But when I try to add percentage labels on the chart
pie <- ggplot(df, aes(x="", y=value, fill=Group)) +
geom_bar(width = 1, stat = "identity") +
coord_polar("y", start=0) +
geom_text(aes(y = value/2 + c(0, cumsum(value)[-length(value)]),
label = percent(value/300 )), size=5)
This is my result.
I have already seen many same question as mine,i.e R + ggplot2 => add labels on facet pie chart and the solutions are not helping.
How about:
vals <- c(239, 52, 9)
val_names <- sprintf("%s (%s)", c("Negative", "Positive", "Neutral"), scales::percent(round(vals/sum(vals), 2)))
names(vals) <- val_names
waffle::waffle(vals) +
ggthemes::scale_fill_tableau(name=NULL)
instead?
It's "fresher" than a pie chart and you aren't really gaining anything with the level of precision you have/want on those pie labels now.
For example, I create a dataframe e3 with 400 vehicles:
e3 <- data.frame(400)
e3 <- rep( c("car", "truck", "other", "bike", "suv"), c(60, 120, 20, 50, 150))
Since pie charts are especially useful for proportions, let's have a look on the proportions of our vehicles, than we will report on the graph in this case:
paste(prop.table(table(e3))*100, "%", sep = "")
[1] "15%" "5%" "30%" "12.5%" "37.5%"
Then you can draw your pie chart,
pie(table(e3), labels = paste(round(prop.table(table(e3))*100), "%", sep = ""),
col = heat.colors(5), main = "Vehicles proportions - n: 400")
Here is an idea matching the order of groups in the pie chart and the order of labels. I sorted the data in descending order by value. I also calculated the percentage in advance. When I drew the ggplot figure, I specified the order of Group in the order in mydf (i.e., Negative, Positive, and Neutral) using fct_inorder(). When geom_label_repel() added labels to the pie, the order of label was identical to that of the pie.
library(dplyr)
library(ggplot2)
library(ggrepel)
library(forcats)
library(scales)
mydf %>%
arrange(desc(value)) %>%
mutate(prop = percent(value / sum(value))) -> mydf
pie <- ggplot(mydf, aes(x = "", y = value, fill = fct_inorder(Group))) +
geom_bar(width = 1, stat = "identity") +
coord_polar("y", start = 0) +
geom_label_repel(aes(label = prop), size=5, show.legend = F, nudge_x = 1) +
guides(fill = guide_legend(title = "Group"))
DATA
mydf <- structure(list(Group = structure(c(3L, 1L, 2L), .Label = c("Negative",
"Neutral", "Positive"), class = "factor"), value = c(52L, 239L,
9L)), .Names = c("Group", "value"), class = "data.frame", row.names = c("1",
"2", "3"))
I agree with #hrbrmstr a waffle chart would be better. But to answer the original question... your problem comes from the order in which the wedges are drawn, which will default to alphabetical. As you calculate where to place the labels based on the ordering in your data frame, this works out wrong.
As a general principle of readability, do all the fancy calculations of labels and positions they go before the actual code drawing the graphic.
library(dplyr)
library(ggplot2)
library(ggmap) # for theme_nothing
df <- data.frame(value = c(52, 239, 9),
Group = c("Positive", "Negative", "Neutral")) %>%
# factor levels need to be the opposite order of the cumulative sum of the values
mutate(Group = factor(Group, levels = c("Neutral", "Negative", "Positive")),
cumulative = cumsum(value),
midpoint = cumulative - value / 2,
label = paste0(Group, " ", round(value / sum(value) * 100, 1), "%"))
ggplot(df, aes(x = 1, weight = value, fill = Group)) +
geom_bar(width = 1, position = "stack") +
coord_polar(theta = "y") +
geom_text(aes(x = 1.3, y = midpoint, label = label)) +
theme_nothing()
This is my example, using only the basic R code. Hope it help.
Take iris for example
attach(iris)
check the the ratio of iris$Species
a<- table(iris$Species)
class(a)
then convert table format into matrix in order to use rowname code
a_mat<- as.matrix(a)
a_mat
calculate the ratio of each Species
a_ratio<- a_mat[,1]/sum(a_mat[,1])*100
a_ratio
since each Species accounts for 0.33333 (i.e. 33.33333%), I just want 2 decimal places by using signif()
a_ratio<- signif(a_ratio,3)
a_ratio
basic pie chart code of R base
pie(a_ratio,labels=rownames(a_mat))
further add ratio values to labels by using paste()
pie(a_ratio,labels=paste(rownames(a_mat),c("33%","33%","34%")))
final pie chart, please click this link

ggplot, facet, piechart: placing text in the middle of pie chart slices

I'm trying to produce a facetted pie-chart with ggplot and facing problems with placing text in the middle of each slice:
dat = read.table(text = "Channel Volume Cnt
AGENT high 8344
AGENT medium 5448
AGENT low 23823
KIOSK high 19275
KIOSK medium 13554
KIOSK low 38293", header=TRUE)
vis = ggplot(data=dat, aes(x=factor(1), y=Cnt, fill=Volume)) +
geom_bar(stat="identity", position="fill") +
coord_polar(theta="y") +
facet_grid(Channel~.) +
geom_text(aes(x=factor(1), y=Cnt, label=Cnt, ymax=Cnt),
position=position_fill(width=1))
The output:
What parameters of geom_text should be adjusted in order to place numerical labels in the middle of piechart slices?
Related question is Pie plot getting its text on top of each other but it doesn't handle case with facet.
UPDATE: following Paul Hiemstra advice and approach in the question above I changed code as follows:
---> pie_text = dat$Cnt/2 + c(0,cumsum(dat$Cnt)[-length(dat$Cnt)])
vis = ggplot(data=dat, aes(x=factor(1), y=Cnt, fill=Volume)) +
geom_bar(stat="identity", position="fill") +
coord_polar(theta="y") +
facet_grid(Channel~.) +
geom_text(aes(x=factor(1),
---> y=pie_text,
label=Cnt, ymax=Cnt), position=position_fill(width=1))
As I expected tweaking text coordiantes is absolute but it needs be within facet data:
NEW ANSWER: With the introduction of ggplot2 v2.2.0, position_stack() can be used to position the labels without the need to calculate a position variable first. The following code will give you the same result as the old answer:
ggplot(data = dat, aes(x = "", y = Cnt, fill = Volume)) +
geom_bar(stat = "identity") +
geom_text(aes(label = Cnt), position = position_stack(vjust = 0.5)) +
coord_polar(theta = "y") +
facet_grid(Channel ~ ., scales = "free")
To remove "hollow" center, adapt the code to:
ggplot(data = dat, aes(x = 0, y = Cnt, fill = Volume)) +
geom_bar(stat = "identity") +
geom_text(aes(label = Cnt), position = position_stack(vjust = 0.5)) +
scale_x_continuous(expand = c(0,0)) +
coord_polar(theta = "y") +
facet_grid(Channel ~ ., scales = "free")
OLD ANSWER: The solution to this problem is creating a position variable, which can be done quite easily with base R or with the data.table, plyr or dplyr packages:
Step 1: Creating the position variable for each Channel
# with base R
dat$pos <- with(dat, ave(Cnt, Channel, FUN = function(x) cumsum(x) - 0.5*x))
# with the data.table package
library(data.table)
setDT(dat)
dat <- dat[, pos:=cumsum(Cnt)-0.5*Cnt, by="Channel"]
# with the plyr package
library(plyr)
dat <- ddply(dat, .(Channel), transform, pos=cumsum(Cnt)-0.5*Cnt)
# with the dplyr package
library(dplyr)
dat <- dat %>% group_by(Channel) %>% mutate(pos=cumsum(Cnt)-0.5*Cnt)
Step 2: Creating the facetted plot
library(ggplot2)
ggplot(data = dat) +
geom_bar(aes(x = "", y = Cnt, fill = Volume), stat = "identity") +
geom_text(aes(x = "", y = pos, label = Cnt)) +
coord_polar(theta = "y") +
facet_grid(Channel ~ ., scales = "free")
The result:
I would like to speak out against the conventional way of making pies in ggplot2, which is to draw a stacked barplot in polar coordinates. While I appreciate the mathematical elegance of that approach, it does cause all sorts of headaches when the plot doesn't look quite the way it's supposed to. In particular, precisely adjusting the size of the pie can be difficult. (If you don't know what I mean, try to make a pie chart that extends all the way to the edge of the plot panel.)
I prefer drawing pies in a normal cartesian coordinate system, using geom_arc_bar() from ggforce. It requires a little bit of extra work on the front end, because we have to calculate angles ourselves, but that's easy and the level of control we get as a result is more than worth it.
I've used this approach in previous answers here and here.
The data (from the question):
dat = read.table(text = "Channel Volume Cnt
AGENT high 8344
AGENT medium 5448
AGENT low 23823
KIOSK high 19275
KIOSK medium 13554
KIOSK low 38293", header=TRUE)
The pie-drawing code:
library(ggplot2)
library(ggforce)
library(dplyr)
# calculate the start and end angles for each pie
dat_pies <- left_join(dat,
dat %>%
group_by(Channel) %>%
summarize(Cnt_total = sum(Cnt))) %>%
group_by(Channel) %>%
mutate(end_angle = 2*pi*cumsum(Cnt)/Cnt_total, # ending angle for each pie slice
start_angle = lag(end_angle, default = 0), # starting angle for each pie slice
mid_angle = 0.5*(start_angle + end_angle)) # middle of each pie slice, for the text label
rpie = 1 # pie radius
rlabel = 0.6 * rpie # radius of the labels; a number slightly larger than 0.5 seems to work better,
# but 0.5 would place it exactly in the middle as the question asks for.
# draw the pies
ggplot(dat_pies) +
geom_arc_bar(aes(x0 = 0, y0 = 0, r0 = 0, r = rpie,
start = start_angle, end = end_angle, fill = Volume)) +
geom_text(aes(x = rlabel*sin(mid_angle), y = rlabel*cos(mid_angle), label = Cnt),
hjust = 0.5, vjust = 0.5) +
coord_fixed() +
scale_x_continuous(limits = c(-1, 1), name = "", breaks = NULL, labels = NULL) +
scale_y_continuous(limits = c(-1, 1), name = "", breaks = NULL, labels = NULL) +
facet_grid(Channel~.)
To show why I think this this approach is so much more powerful than the conventional (coord_polar()) approach, let's say we want the labels on the outside of the pie rather than inside. This creates a couple of problems, such as we will have to adjust hjust and vjust depending on the side of the pie a label falls, and also we will have to make the
plot panel wider than high to make space for the labels on the side without generating excessive space above and below. Solving these problems in the polar coordinate approach is not fun, but it's trivial in the cartesian coordinates:
# generate hjust and vjust settings depending on the quadrant into which each
# label falls
dat_pies <- mutate(dat_pies,
hjust = ifelse(mid_angle>pi, 1, 0),
vjust = ifelse(mid_angle<pi/2 | mid_angle>3*pi/2, 0, 1))
rlabel = 1.05 * rpie # now we place labels outside of the pies
ggplot(dat_pies) +
geom_arc_bar(aes(x0 = 0, y0 = 0, r0 = 0, r = rpie,
start = start_angle, end = end_angle, fill = Volume)) +
geom_text(aes(x = rlabel*sin(mid_angle), y = rlabel*cos(mid_angle), label = Cnt,
hjust = hjust, vjust = vjust)) +
coord_fixed() +
scale_x_continuous(limits = c(-1.5, 1.4), name = "", breaks = NULL, labels = NULL) +
scale_y_continuous(limits = c(-1, 1), name = "", breaks = NULL, labels = NULL) +
facet_grid(Channel~.)
To tweak the position of the label text relative to the coordinate, you can use the vjust and hjust arguments of geom_text. This will determine the position of all labels simultaneously, so this might not be what you need.
Alternatively, you could tweak the coordinate of the label. Define a new data.frame where you average the Cnt coordinate (label_x[i] = Cnt[i+1] + Cnt[i]) to position the label in the center of that particular pie. Just pass this new data.frame to geom_text in replacement of the original data.frame.
In addition, piecharts have some visual interpretation flaws. In general I would not use them, especially where good alternatives exist, e.g. a dotplot:
ggplot(dat, aes(x = Cnt, y = Volume)) +
geom_point() +
facet_wrap(~ Channel, ncol = 1)
For example, from this plot it is obvious that Cnt is higher for Kiosk than for Agent, this information is lost in the piechart.
Following answer is partial, clunky and I won't accept it.
The hope is that it will solicit better solution.
text_KIOSK = dat$Cnt
text_AGENT = dat$Cnt
text_KIOSK[dat$Channel=='AGENT'] = 0
text_AGENT[dat$Channel=='KIOSK'] = 0
text_KIOSK = text_KIOSK/1.7 + c(0,cumsum(text_KIOSK)[-length(dat$Cnt)])
text_AGENT = text_AGENT/1.7 + c(0,cumsum(text_AGENT)[-length(dat$Cnt)])
text_KIOSK[dat$Channel=='AGENT'] = 0
text_AGENT[dat$Channel=='KIOSK'] = 0
pie_text = text_KIOSK + text_AGENT
vis = ggplot(data=dat, aes(x=factor(1), y=Cnt, fill=Volume)) +
geom_bar(stat="identity", position=position_fill(width=1)) +
coord_polar(theta="y") +
facet_grid(Channel~.) +
geom_text(aes(y=pie_text, label=format(Cnt,format="d",big.mark=','), ymax=Inf), position=position_fill(width=1))
It produces following chart:
As you noticed I can't move labels for green (low).

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