Create a barplot in R by a column value

Question

For example, let the data frame, df, be

Location	Snowfall
London	0.4
London	1.3
NYC	4.3
NYC	0.2
Paris	3.0
London	2.0

Is there a way to make a bar graph of the total snowfall by location?

London's bar length would be 3.7 and so on...

Answer 1

In base R, you can first aggregate and then use barplot.

barplot(Snowfall~Location, aggregate(Snowfall~Location, df, sum))

Answer 2

Here a tidyverse approach

Data

df <-
tibble::tribble(
  ~Location, ~Snowfall,
   "London",       0.4,
   "London",       1.3,
      "NYC",       4.3,
      "NYC",       0.2,
    "Paris",         3,
   "London",         2
  ) 

Plot

library(dplyr)
library(ggplot2)


df %>% 
  #Grouping by Location
  group_by(Location) %>% 
  #Sum of Snowfall by Location
  summarise(Snowfall = sum(Snowfall)) %>% 
  ggplot(aes(Location,Snowfall))+     
  geom_col(width = .5)