Going from a dataframe with a factor column and numeric column to a dataframe with factor levels as-CodePudding

If I take the following two-column dataframe, with one column being a factor and the other being a numeric vector:

data <- data.frame(x=c("a","b","c","d","e","f","g","h"), y = c(1,2,3,3,2,1,5,6))
data$x <- as.factor(data$x)

How can I turn it into a new dataframe data2 where the factor levels of data$x are columns and the rows contain the corresponding numeric values from data$y, like so?

structure(list(a = 1, b = 2, c = 3, d = 3, e = 2, f = 1, g = 5, 
    h = 6), class = "data.frame", row.names = c(NA, -1L))

CodePudding user response：

With base R, use rbind.data.frame:

d <- rbind.data.frame(data$y)
colnames(d) <- data$x

  a b c d e f g h
1 1 2 3 3 2 1 5 6

With pivot_wider:

tidyr::pivot_wider(data, names_from = x, values_from = y)

      a     b     c     d     e     f     g     h
1     1     2     3     3     2     1     5     6

or with xtabs:

xtabs(y ~ ., data = data) |> 
    as.data.frame.list()

  a b c d e f g h
1 1 2 3 3 2 1 5 6

CodePudding user response：

Another possible solution, using data.table::transpose:

data.table::transpose(data, make.names = 1)

#>   a b c d e f g h
#> 1 1 2 3 3 2 1 5 6