Pivoting data but keeping it aligned in R?

July 26, 2022

I have a big dataframe in R that looks like the following:

Age   Gene1   Gene2   Gene3 
33     0       1       1
57     1       0       1
90     1       1       1

I’m trying to plot this data in a bar graph, with the frequency that the genes are plotted against the age. When I try to pivot the data using:

pivoted_df <- df %>%
pivot_longer(AGE, names_to="genes", values_to="count")

This does pivot the data but my resulting dataframe looks like this:

Age  Gene  Count
33   Gene1   0
33   Gene2   1
33   Gene3   1  
57   Gene1   1
57   Gene2   0
57   Gene3   1
90   Gene1   1
90   Gene2   1
90   Gene3   1

Is there a way for me to pivot the data without repeating the ages? I.E still keep the genes and the count columns, but assign multiple values from that to one age?

>Solution :

Maybe you want this where you reshape your data from wide to long using melt and create the "Age" as.factor to plot stacked bars like this:

df <- read.table(text = "Age   Gene1   Gene2   Gene3 
33     0       1       1
57     1       0       1
90     1       1       1", header = TRUE)

library(dplyr)
library(ggplot2)
library(reshape)
df %>%
  melt(id.vars = "Age") %>%
  mutate(Age = as.factor(Age)) %>%
  ggplot(aes(x = Age, y = value, fill = variable)) +
  geom_col() +
  labs(fill = "gene", y = "count") +
  theme_bw()