Spread() with multiple `value` columns

tidyverse
2

You can do this by using quosures. I think that the reprex ( https://www.jessemaegan.com/post/so-you-ve-been-asked-to-make-a-reprex ) below has the function you want.


suppressPackageStartupMessages(library(tidyverse))
df <- data.frame(month=rep(1:3,2),
                                 student=rep(c("Amy", "Bob"), each=3),
                                 A=c(9, 7, 6, 8, 6, 9),
                                 B=c(6, 7, 8, 5, 6, 7))

t1 <- df %>%
    gather(variable, value, -(month:student)) %>%
    unite(temp, student, variable) %>%
    spread(temp, value)

myspread <- function(df, key, value) {
    # quote key
    keyq <- rlang::enquo(key)
    # break value vector into quotes
    valueq <- rlang::enquo(value)
    s <- rlang::quos(!!valueq)
    df %>% gather(variable, value, !!!s) %>%
        unite(temp, !!keyq, variable) %>%
        spread(temp, value)
}

t2 <- df %>% myspread(student, c(A, B))

identical(t1, t2)
#> [1] TRUE

t2
#>   month Amy_A Amy_B Bob_A Bob_B
#> 1     1     9     6     8     5
#> 2     2     7     7     6     6
#> 3     3     6     8     9     7

Created on 2018-02-20 by the reprex package (v0.2.0).

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