bar chart, ggplot formula

[jaqo]

Hi Community,

I am looking to get a bar chart viz function right such as: ggplot(data, aes(x=?)) + geom_bar() The x-axis should indicate 3 distinct columns a, b, and c where each has a total value (a=8, b=10, c=13). In the formula where I wrote x=?, how can x represent all 3 columns total? Thanks,

[williaml]

Can you provide a reproducible example?

FAQ: How to do a minimal reproducible example ( reprex ) for beginners

A minimal reproducible example consists of the following items: A minimal dataset, necessary to reproduce the issue The minimal runnable code necessary to reproduce the issue, which can be run on the given dataset, and including the necessary information on the used packages. Let's quickly go over each one of these with examples: Minimal Dataset (Sample Data) You need to provide a data frame that is small enough to be (reasonably) pasted on a post, but big enough to reproduce your issue. Let's say, as an example, that you are working with the iris data frame head(iris) #> Sepal.Length Sepal.Width Petal.Length Petal.Width Species #> 1 5.1 3.5 1.4 0.…

[jaqo]

This is the ggplot function I am trying to get right. ggplot(data, aes(x=?))+ geom_bar() I want x to represent 3 different values such as: value a, which is equal to 8, value b = 10, and value c = 13. How can I represent all 3 on the formula (x=?).

[williaml]

Can you provide some data?

[jaqo]

I already presented data. I want to have 3 columns on x-axis. column 'a' has a value of 8, column 'b' has 10, and column 'c' has 13. This is the formula I am trying to include the 3 columns on x: ggplot(data, aes(x=...)) + geom_bar()

[williaml]

That's code, not data. Have a look at the article and make your post reproducible.

[jaqo]

Try this link and check out gold, silver, and bronze medals. Those 3 columns (each totaled) need to be visualized as a bar chart, on x-axis

Tokyo 2020 Olympic Medal Table - Gold, Silver & Bronze

[nirgrahamuk]

library(tidyverse)

mydata <- data.frame(
  name=letters[1:3],
  value =c(8,10,13)
)

ggplot(mydata, aes(x=name,
                   y=value)) + geom_col()

you may benefit from studying this useful book.
https://r4ds.had.co.nz/

[jaqo]

Thanks buddy! In the formula where you wrote: name=letters[1:3], where do the 3 columns names fit in? I have column named: gold, silver, and bronze

[nirgrahamuk]

letters is simply a built-in to R vector of the lowercase letters.
You can substitute for any size 3 vector given that the data.frame is 3 entries.
For general info on what vectors are in R , try a resource like
20 Vectors | R for Data Science (had.co.nz)

[DrMowinckels]

You need to transform your data into a longer format if you have the values you want plotted in different columns. ggplot2 likes working with long formatted data, so learning data transformations is key to ggplot success.

library(tidyverse)

# Create the data
data <- tibble(
  a = 8, 
  b = 10, 
  c = 13
)

data
#> # A tibble: 1 x 3
#>       a     b     c
#>   <dbl> <dbl> <dbl>
#> 1     8    10    13

# Make the data long,
# Transforms the data to something ggplot likes
data_long <- data %>% 
  pivot_longer(everything())

data_long
#> # A tibble: 3 x 2
#>   name  value
#>   <chr> <dbl>
#> 1 a         8
#> 2 b        10
#> 3 c        13

ggplot(data_long) + 
  geom_bar(aes(x = name, 
               y = value), 
           stat = "identity") # use value from the data

^{Created on 2021-08-19 by the reprex package (v2.0.0)}

[jaqo]

Thanks! This is truly the answer I was seeking.