问题
I'd like to plot a barplot of frequency density of the following ordered categorical data:
summary(ACC[EA$TYPE=="A"])
NG SG LG MG HG
2 25 36 17 0
If I plot:
plot(ACC[EA$TYPE=="A"])
I get:
But I'd like to divide all the values by the total to get a frequency density:
Ie.
plot(ACC[EA$TYPE=="A"]/sum(as.numeric(ACC[EA$TYPE=="A"]))) but that doesn't work. Any tips?
Cheers,
回答1:
The default plotting function for a factor is barplot. So if you want a different graph, it may be easier to directly use this function: (with a random factor example)
f <- factor(sample(letters[1:5], 100, r=T))
h <- table(f) / length(f)
barplot(h)
Getting the same result with ggplot2 is trickier, and for some reason, I needed to put the data in a data.frame for it to work:
dat <- data.frame(f = f)
library(ggplot2)
ggplot(dat, aes(x=f, y=..count.. / sum(..count..), fill=f)) + geom_bar()
回答2:
It would be easier to fix it with a reproducible example, so I created one for you. The following works like a charm:
# creates the vector
x <- c(2, 25, 36, 17, 0)
names(x) <- c("NG", "SG", "LG", "MG", "HG")
# raw x = counts
barplot(x, ylab="Count")
# when divided by the total count, we obtain frequencies and we barplot them
barplot(x/sum(x), ylab="Frequency")
I see no reason why this could not work as long as ACC[EA$TYPE=="A"] is a numeric:
barplot(ACC[EA$TYPE=="A"]/sum(ACC[EA$TYPE=="A"]), ylab="Frequency")
来源：https://stackoverflow.com/questions/36495155/frequency-density-barplot-of-categorical-variable