CODEWITHSUNDEEP
rplotggplot2
user3240688
user3240688

Reputation: 1325

How do I create a bar plot in R where each bar is the percentage of a categorical var for a group?

Say I have data in the following format:

categoricalVar,  numericVar,  responseVar
           Foo,           1,         TRUE
           Bar,           0,         TRUE
           Baz,           2,        FALSE
       ...
       ...
       ... MUCH MUCH MORE

I want to create a bar plot where the X axis would be the 3 different types of categoricalVar, and Y axis would the percentage of them that turned out to be TRUE. A table would work too, like this. 

           Foo,   Bar,   Baz
 respPct   0.4,   0.6,   0.9

So out of all the Foos, the percentage of TRUE was 0.4.

The same thing for numericVar would be nice. 

             0,     1,     2, ....
 respPct   0.1,   0.2,   0.2

Although I think it makes sense to group the numericVar together, as follows:

           0-5,  5-10, 10-15, ....
 respPct   0.2,   0.3,   0.6

Can someone point me in the right direction?

Upvotes: 0

Views: 60

Answers (2)

Jaap
Jaap

Reputation: 83255

First you have to transform your numericVar into a categorial variable. But let's first create some example data:

set.seed(2)
df <- data.frame(catVar = rep(c("foo","bar","saz"),each=10),
                 respVar = c(sample(c(TRUE,TRUE,TRUE,FALSE,TRUE), 10, replace =TRUE),
                             sample(c(FALSE,TRUE,TRUE,FALSE,TRUE), 10, replace =TRUE),
                             sample(c(FALSE,FALSE,TRUE,FALSE,TRUE), 10, replace =TRUE)),
                 numVar = sample(0:15, 30, replace =TRUE))

1: create a categorical variable for numVar with:

df$catNum <- cut(df$numVar, breaks = c(-Inf,5,10,Inf), labels = c("0-5", "5-10", "10-15"))

2: aggregate the data with:

df2 <- aggregate(respVar ~ catVar, df, FUN = function(x) sum(x)/length(x))
df3 <- data.frame(table(df$catNum)/30)

3: create some plots with:

ggplot(df2, aes(x=catVar, y=respVar)) +
  geom_bar(stat="identity")

enter image description here

ggplot(df3, aes(x=Var1, y=Freq)) +
  geom_bar(stat="identity")

enter image description here

Upvotes: 3

Mateusz1981
Mateusz1981

Reputation: 1867

   df <- data.frame(a = c("0-5", "5-10", "10-15"), respPct =  c(0.2,   0.3,   0.6))
    library(ggplot2)
    ggplot(aes( x= a, y = respPct), data = df) + geom_bar(stat = "identity")

enter image description here

Upvotes: 1

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