CODEWITHSUNDEEP
rggplot2
Prajwal Mani Pradhan
Prajwal Mani Pradhan

Reputation: 397

How to create multiple barcharts in a loop?

Few rows of my data are like:

enter image description here

I am trying to write a loop program in R that takes a set of rows with similar names/values and produces the bar plots in a loop for rows with similar names/values stored in a single column "Variable_name" in R.

so far, I have tried to create a separate data table for each set of rows, filtering by row values and then passing it to ggplot.

[Works but don't want to go through this process] Tedious/Manual process:

data[is.na(data)]<-'NA' #Turning NA as a valid value so that it get's included in the bar diagram.

bar_data1 <- data %>%
filter(Variable_name == 'Gender')

ggplot(bar_data1, aes(x=Levels, y=Count, fill=Levels))+geom_bar(stat="identity")+theme_minimal()+scale_y_continuous(breaks=c(0,10,20,50,100,150))

[Want but doesn't work] I also tried this for loop:

for(i in 1:2){
print(ggplot(data, aes(x=Levels, y=Count, fill=Levels))+geom_bar(stat="identity")+theme_minimal()+scale_y_continuous(breaks=c(0,10,20,50,100,150)))
}

The issue with the loop program that I have written is that it runs forever and ultimately R stops responding. Is it running out of memory? I think there is something wrong with my loop program.

Any advice on how to make it work through the loop program?

Upvotes: 2

Views: 1333

Answers (2)

pietrodito
pietrodito

Reputation: 2090

This is an example with mtcars. We gonna plot 3 histograms with 3 groups based on the number of cyl of the cars:

Instead of a for loop we gonna use the purrr::map() function :

library(tidyverse)

groups <- names(table(mtcars$cyl))

plots <- map(groups,
     function(group) {
       (
         mtcars
         %>% filter(cyl == group)
         %>% ggplot(aes(hp))
          +  geom_histogram()
       )})

print(plots)

But if you want to plot all histograms on the same figure, use facet_wrap():

(
    mtcars
    %>% ggplot(aes(hp))
     +  geom_histogram()
     +  facet_wrap(~cyl)
)

Upvotes: 3

Giulio Centorame
Giulio Centorame

Reputation: 700

If I understood the question correctly and you want to use a for loop, you are looking at something like this (the example is untested):

for(value in names(table(data$Variable_name))){

     assign(paste0("data_", value), filter(data, Variable_name == value))

     ggplot(paste0("data_", value), aes(x=Levels, y=Count, fill=Levels))+
      geom_bar(stat="identity")+
      theme_minimal()+
      scale_y_continuous(breaks=c(0,10,20,50,100,150))
}

Upvotes: 0

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