How to create an alluvial plot in ggplot2 with ggalluvial package?

Question

I'm trying to create an alluvial plot in ggplot2 with the ggalluvial package. Here are the two helpful websites I've been using to create the plot: site 1 and site 2.

My goal is to use the same code found on site 1 but apply it to my own df, as shown below. However, everytime I try to do that I get the following error:

Error in data.frame(first_row, curve_data): arguments imply differing number of rows: 1, 12

This is my df:

t1 <- c("college", "college", "college", "university", "university")
t2 <- c("law", "law", "business", "business", "business")
t3 <- c("public", "private", "private", "private", "public")
t4 <- c(2,4,6,8,10)

df <- data.frame(cbind(t1,t2,t3,t4))
names(df) <- c("Undergrad", "Grad_School", "Sector", "Freq")

This is the original code, as copied from site 1:

library(ggalluvial)
vaccinations
ggplot(data = vaccinations,
       aes(axis1 = survey,
           axis2 = response,
           axis3 = survey,
           y = freq)) +
    geom_alluvium(aes(fill = response)) +
    geom_stratum() +
    geom_text(stat = "stratum",
              aes(label = after_stat(stratum))) +
    scale_x_discrete(limits = c("Survey", "Response"),
                     expand = c(0.15, 0.05)) +
    theme_void()

This is my code with my df substituted in.

ggplot(data = df,
       aes(axis1 = Undergrad,
           axis2 = Grad_School,
           y = Freq)) +
    geom_alluvium(aes(fill = Sector)) +
    geom_stratum() +
    geom_text(stat = "stratum",
              aes(label = after_stat(stratum))) +
    scale_x_discrete(limits = c("Undergrad", "Grad_School"),
                     expand = c(0.15, 0.05)) +
    theme_void()

Please share the exact code you're currently trying so we can help. How did you modify the code from the example to use your data? — Dan Adams, Jul 18 '22 at 04:46
@DanAdams, thanks for your comment. I edited the question to show how I modified the code. — Sly, Jul 18 '22 at 05:23
Your code works fine for me. If you clear your environment and start again, does it still give an error? — Dan Adams, Jul 18 '22 at 05:25
Unfortunately, I'm still getting the same error. Your answer below worked perfectly. I'm still trying to understand why my code didn't work. It seems very similar to your answer. — Sly, Jul 18 '22 at 05:40
Just updated the answer. Compare `str(df)` to `str(d)` and you'll see that yours has `chr` for `Freq` which is why it won't work. — Dan Adams, Jul 18 '22 at 05:42

Dan Adams · Accepted Answer · 2022-07-18T06:08:40.130

When you cbind() your vectors, you create a matrix which (unlike a data.frame) cannot contain different data types. Therefore, the Freq gets converted to a character. If you just directly create the data.frame without cbind() it works fine.

library(tidyverse)
library(ggalluvial)

t1 <- c("college", "college", "college", "university", "university")
t2 <- c("law", "law", "business", "business", "business")
t3 <- c("public", "private", "private", "private", "public")
t4 <- c(2,4,6,8,10)

df <- data.frame(t1,t2,t3,t4)
names(df) <- c("Undergrad", "Grad_School", "Sector", "Freq")

ggplot(data = df, 
       aes(axis1 = Undergrad,
             axis2 = Grad_School,
             y = Freq)) +
  geom_alluvium(aes(fill = Sector)) +
  geom_stratum() +
  geom_text(stat = "stratum",
            aes(label = after_stat(stratum))) +
  scale_x_discrete(limits = c("Undergrad", "Grad_School"),
                   expand = c(0.15, 0.05)) +
  theme_void()

^{Created on 2022-07-18 by the reprex package (v2.0.1)}

How to create an alluvial plot in ggplot2 with ggalluvial package?

1 Answers1