Problem creating alluvial diagram using ggalluvial

Question

I have this dataset:

type <- c(1, 2, NA, 1, 2, NA)
freq <- c(75, 12, 25, 69, 22, 32)
time <- c("before", "before", "before", "after", "after", "after")

df <- data.frame(type , freq, time )

I need to make a graph like this (with different data obviously):

I tried to follow the guide here: https://cran.r-project.org/web/packages/ggalluvial/vignettes/ggalluvial.html

Using this code:

ggplot(modechoice,
       aes(x = time, stratum = type, alluvium = time,
           y = freq,
           fill = type, label = type)) +
  scale_x_discrete(expand = c(.1, .1)) +
  geom_flow() +
  geom_stratum(alpha = .5) +
  geom_text(stat = "stratum", size = 3) +
  theme(legend.position = "none") +
  ggtitle("x")

But I get the error that my data is not recognised as an alluvial. What am I doing wrong?

Answer 1

You should have a fourth variable which is linked with your time variable, that's why I created an extra variable as an example. You can use the following code:

type <- c("1", "2", "NA", "1", "2", "NA")
freq <- c(75, 12, 25, 69, 22, 32)
time1 <- c("before", "before", "before", "after", "after", "after")
time2 <- c("after", "before", "after", "after", "before", "after") 


df <- data.frame(type , freq, time1, time2)

library(tidyverse)
library(ggalluvial)

ggplot(df,
       aes(y = freq, axis1 = time1, axis2 = time2)) +
  geom_alluvium(aes(fill = type), width = 1/12) +
  geom_stratum(width = 1/12, fill = "black", color = "grey") +
  geom_label(stat = "stratum", aes(label = after_stat(stratum))) +
  scale_x_discrete(limits = c("time1", "time2"), expand = c(.05, .05)) +
  scale_fill_brewer(type = "qual", palette = "Set1") +
  ggtitle("x")

Output:

Edit after Victor Nielson comment:

    type <- c("1", "2", "NA", "1", "2", "NA")
freq <- c(75, 12, 25, 69, 22, 32)
time1 <- c("before", "before", "before", "before", "before", "before")
time2 <- c("after", "after", "after", "after", "after", "after") 


df <- data.frame(type , freq, time1, time2)

library(tidyverse)
library(ggalluvial)

ggplot(df,
       aes(y = freq, axis1 = time1, axis2 = time2)) +
  geom_alluvium(aes(fill = type), width = 1/12) +
  geom_stratum(width = 1/12, fill = "black", color = "grey") +
  geom_label(stat = "stratum", aes(label = after_stat(stratum))) +
  scale_x_discrete(limits = c("time1", "time2"), expand = c(.05, .05)) +
  scale_fill_brewer(type = "qual", palette = "Set1") +
  ggtitle("x")

Output: