How to melt into columns row results?

Question

From a frame like this:

df <- data.frame(year = c(2010,2010,2011,2011), stock = c("Amazon","Google","Yahoo","Google")

How can we melt the rows and convert into columns count results? The expected output:

   stock 2010 2011
Amazon     1     0
Google     1     1
Yahoo     0     1

Answer 1

table(rev(df))
#         year
# stock    2010 2011
#   Amazon    1    0
#   Google    1    1
#   Yahoo     0    1

rev() is to have the desired output directly, otherwise transpose with t(table(df)))

Or equivalently:

• table(df[2:1]) (by Sotos)
• table(df$stock, df$year) (by Quang Hoang)

Answer 2

library(janitor)
df %>% tabyl(stock, year)                 
#>   stock 2010 2011
#>  Amazon    1    0
#>  Google    1    1
#>   Yahoo    0    1