How to create multiple columns from a single column in R

September 21, 2022

I have a large data set in which i have a column which contains 5 different types of values. I want to create 5 different columns( 1 for each value) based on the column. Additionally, each row in those columns should contain either 1 or 0 based on whether another column contained that value
For example suppose this is the data frame

l1=data.frame(c1=  c("A","A","B","B","B","C"), c2 = c("Blue","Green","Red","yellow","Black","Blue"))

The output should be

l2=data.frame(c1=c("A","A","B","B","B","C"), Blue=c(1,0,0,0,0,1),Green=c(0,1,0,0,0,0),Red=c(0,0,1,0,0,0),Yellow=c(0,0,0,1,0,0),Black=c(0,0,0,0,1,0))

Thank you!

>Solution :

library(tidyverse)
l1 %>%
  mutate(n = 1, dummy = row_number()) %>%
  pivot_wider(names_from = c2, values_from = n, values_fill = 0) %>%
  select(-dummy)

Result

# A tibble: 6 × 6
  c1     Blue Green   Red yellow Black
  <chr> <dbl> <dbl> <dbl>  <dbl> <dbl>
1 A         1     0     0      0     0
2 A         0     1     0      0     0
3 B         0     0     1      0     0
4 B         0     0     0      1     0
5 B         0     0     0      0     1
6 C         1     0     0      0     0