How to create a ggplot bar chart with multiple columns of data for y?

Question

My dataset looks like this :

Here's a table with a sample of the data:

City	AverageClientUsage	AverageClientEst	EstimatedTraffic
Atlanta	2695.68	3555.62	2812.89
Boston	559.48	1080.49	583.81
Chicago	3314.44	5728	3458.56

I'd like ggplot to use City as the X axis and have three bars for each point on the x axis, one for AverageClientUsage, one for AverageClientEst, one for EstimatedTraffic. How do I go about doing this? At the end I'd like the ggplot to look like this:

Answer 1

First, you need to pivot_longer() your dataframe:

library(dplyr)
df_long <- df %>% pivot_longer(!City, names_to = "Type", values_to = "Count")

Afterwards, you can create bars filled by Type, and using position = "dodge" within geom_col()

library(ggplot)
ggplot(df_long, aes(x = City, y = Count, fill = Type)) + # specify x and y axis, specify fill
         geom_col(position = position_dodge(0.7), width = 0.6, color = "black") + # position.dodge sets the bars side by side
  theme_minimal() + # add a ggplot theme
  theme(legend.position = "bottom", # move legend to bottom
        legend.title = element_blank(), # remove legend title
        axis.text.x = element_text(angle = 45, vjust = 0.5, color = "gray33"), # rotate x axis text by 45 degrees, center again, change color
        axis.text.y = element_text(color = "gray33"), # change y axis text coor
        axis.title = element_blank(), # remove axis titles
        panel.grid.major.x = element_blank()) + # remove vertical grid lines
  scale_fill_manual(values = c("blue", "darkorange2", "gray")) # adjust the bar colors

Data

df <- structure(list(City = c("Atlanta", "Boston", "Chicago"), AverageClientUsage = c(2695.68, 
      559.48, 3314.44), AverageClientEst = c(3555.62, 1080.49, 5728
      ), EstimatedTraffic = c(2812.89, 583.81, 3458.56)), class = c("tbl_df", 
      "tbl", "data.frame"), row.names = c(NA, -3L))