r - Calculate % within a Sub Group using Dplyr - r

Question

I want to chart the relative no of fatalities by year for each of various event types.
I can do with with facets in ggplot but am struggling to calculate the % By Event based on Event, Year and no of fatalities.
Event Type Year Fatalities % by Event
(calculated)
----- ---- ---------- ----------
Storm 1980 5 12.5%
Storm 1981 9 22.5%
Storm 1982 15 37.5%
Storm 1983 11 27.5%
Ice 1980 7 70%
Ice 1981 3 30%
I have the following code to calculate it, but the calculation is not working with the % using a much higher denominator.
fatalitiesByYearType <- stormDF %>%
group_by(eventType) %>%
mutate(totalEventFatalities = sum(FATALITIES)) %>%
group_by(year, add = TRUE) %>%
mutate(fatalitiesPct = sum(FATALITIES) / totalEventFatalities)
What am I doing wrong?
My charting as a below. I include this in case as I'm also interested to see whether there is a way of showing data in a proportionate way within ggplot.
p <- ggplot(data = fatalitiesByYearType,
aes(x=factor(year),y=fatalitiesPct))
p + geom_bar(stat="identity") +
facet_wrap(.~eventType, nrow = 5) +
labs(x = "Year",
y = "Fatalities",
title = "Fatalities by Type")

Answer 1

Maybe I do not get your problem, but we can start from here:
library(dplyr)
library(ggplot2)
# here the dplyr part
dats <- fatalitiesByYearType %>%
group_by(eventType) %>%
mutate(totalEventFatalities = sum(FATALITIES)) %>%
group_by(year, add = TRUE) %>%
# here we add the summarise
summarise(fatalitiesPct = sum(FATALITIES) / totalEventFatalities)
dats
# A tibble: 6 x 3
# Groups: eventType [?]
eventType year fatalitiesPct
<fct> <int> <dbl>
1 Ice 1980 0.7
2 Ice 1981 0.3
3 Storm 1980 0.125
4 Storm 1981 0.225
5 Storm 1982 0.375
6 Storm 1983 0.275
You can clearly merge everything in an unique dplyr chain:
# here the ggplot2 part
p <- ggplot(dats,aes(x=factor(year),y=fatalitiesPct)) +
geom_bar(stat="identity") +
facet_wrap(.~eventType, nrow = 5) +
labs(x = "Year", y = "Fatalities", title = "Fatalities by Type") +
# here we add the % in the plot
scale_y_continuous(labels = scales::percent)
With data:
fatalitiesByYearType <- read.table(text = "eventType year FATALITIES
Storm 1980 5
Storm 1981 9
Storm 1982 15
Storm 1983 11
Ice 1980 7
Ice 1981 3 ",header = T)