Plot a simple conversion funnel in ggplot

Question

I have a simple dataframe that looks like this:

df
   steps  numbers     rate
 1 clicks 332835  100.000000
 2 signup  157697  47.379933
 3  cart   29866   8.         


        

Answer 1

If you must do the funnel thing, it's just a variation on bar chart:

library(ggplot2)
library(reshape2) # for melt()

# get data
dat <- read.table(text=
"steps  numbers     rate
clicks 332835  100.000000
signup  157697  47.379933
cart   29866   8.973215
buys   17012   5.111241", 
header = T)

# add spacing, melt, sort
total <- subset(dat, rate==100)$numbers
dat$padding <- (total - dat$numbers) / 2
molten <- melt(dat[, -3], id.var='steps')
molten <- molten[order(molten$variable, decreasing = T), ]
molten$steps <- factor(molten$steps, levels = rev(dat$steps))

ggplot(molten, aes(x=steps)) +
  geom_bar(aes(y = value, fill = variable),
           stat='identity', position='stack') +
  geom_text(data=dat, 
            aes(y=total/2, label= paste(round(rate), '%')),
            color='white') +
  scale_fill_manual(values = c('grey40', NA) ) +
  coord_flip() +
  theme(legend.position = 'none') +
  labs(x='stage', y='volume')

That said, there's no real point in a "funnel chart" - the same information can be presented in a plain bar chart with less fuss:

# get data
dat <- read.table(text=
"steps  numbers     rate
clicks 332835  100.000000
signup  157697  47.379933
cart   29866   8.973215
buys   17012   5.111241", 
header = T)

# order x axis
dat$steps <- factor(dat$steps, levels = dat$steps)

# plot
ggplot(dat, aes(x=steps, y=numbers)) +
  geom_bar(stat='identity') +
  geom_text(aes(label = paste(round(rate), '%')), vjust=-0.5