melt data.frames with non-atomic 'measure' columns

[cnjr2]

Is it possible to gather() a data frame when it contains list elements?

library("dplyr")
library("tidyr")
library("purrr")

data <- data_frame(
    name = c("Alex", "Alex", "Alex", "Tim", "Tim", "Tim"),
    year = c(1990, 1991, 1992, 1990, 1991, 1992),
    height = c(160, 165, 170, 120, 134, 150),
    weight = c(50, 52, 53, 48, 48, 52)
)

models <- data %>%
    group_by(name) %>%
    nest() %>%
    mutate(
        lm = map(data, ~lm(year ~ height, data = .)),
        lm2 = map(data, ~lm(year ~ height + weight, data = .))
    )

models

This produces the following output:

   name           data      lm     lm2
  (chr)          (chr)   (chr)   (chr)
1  Alex <tbl_df [3,3]> <S3:lm> <S3:lm>
2   Tim <tbl_df [3,3]> <S3:lm> <S3:lm>

Now I would want to gather() this into a long format:

models %>% gather(variabe, value, -name, -data)

But I get:

Error: Can't melt data.frames with non-atomic 'measure' columns

I would like to end up with final data frame like this:

   name            data  variable    value
  (chr)           (chr)     (chr)    (chr)
1  Alex  <tbl_df [3,3]>        lm  <S3:lm>
2  Alex  <tbl_df [3,3]>       lm2  <S3:lm>
3   Tim  <tbl_df [3,3]>        lm  <S3:lm>
4   Tim  <tbl_df [3,3]>       lm2  <S3:lm>

[hadley]

Turned out to be way easier than I thought it would be!

[GauravShraddha]

Hey I am also facing the same issue in my summer project. I would be immensely grateful if you share how you resolved it?