# DataFrame unmelt-like operation

**URL:** <https://discourse.julialang.org/t/dataframe-unmelt-like-operation/7875>\
**Category:** Data\
**Tags:** question\
**Created:** [December 20, 2017, 11:30am UTC](https://discourse.julialang.org/t/dataframe-unmelt-like-operation/7875 "2017-12-20T11:30:19Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Tamas\_Papp](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tamas_papp/32/25949_2.png) [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)\
**Post date:** [December 20, 2017, 11:30am UTC](https://discourse.julialang.org/t/dataframe-unmelt-like-operation/7875/1 "2017-12-20T11:30:19Z")

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I have a `DataFrame` with observations for 2 individuals in a household, and want to “unmelt” it so that they end up in columns, one for each person. MWE:

```julia
julia> df = DataFrame(household = repeat(1:5, inner = 2),
                      person = repeat(1:2, outer = 5),
                      a = 1:10,
                      b = 11:20)
10×4 DataFrames.DataFrame
│ Row │ household │ person │ a │ b │
├─────┼───────────┼────────┼────┼────┤
│ 1 │ 1 │ 1 │ 1 │ 11 │
│ 2 │ 1 │ 2 │ 2 │ 12 │
│ 3 │ 2 │ 1 │ 3 │ 13 │
│ 4 │ 2 │ 2 │ 4 │ 14 │
│ 5 │ 3 │ 1 │ 5 │ 15 │
│ 6 │ 3 │ 2 │ 6 │ 16 │
│ 7 │ 4 │ 1 │ 7 │ 17 │
│ 8 │ 4 │ 2 │ 8 │ 18 │
│ 9 │ 5 │ 1 │ 9 │ 19 │
│ 10 │ 5 │ 2 │ 10 │ 20 │

## this is what the end result should look like
julia> DataFrame(household = 1:5,
                 a_1 = 1:2:9,
                 a_2 = 2:2:10,
                 b_1 = 11:2:19,
                 b_2 = 12:2:20)
5×5 DataFrames.DataFrame
│ Row │ household │ a_1 │ a_2 │ b_1 │ b_2 │
├─────┼───────────┼─────┼─────┼─────┼─────┤
│ 1 │ 1 │ 1 │ 2 │ 11 │ 12 │
│ 2 │ 2 │ 3 │ 4 │ 13 │ 14 │
│ 3 │ 3 │ 5 │ 6 │ 15 │ 16 │
│ 4 │ 4 │ 7 │ 8 │ 17 │ 18 │
│ 5 │ 5 │ 9 │ 10 │ 19 │ 20 │

```

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<div class="post-metadata">

**Author:** ![bkamins](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/bkamins/32/208538_2.png) [@bkamins](https://discourse.julialang.org/u/bkamins)\
**Post date:** [December 20, 2017, 11:53am UTC](https://discourse.julialang.org/t/dataframe-unmelt-like-operation/7875/2 "2017-12-20T11:53:49Z")

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Those are the simplest I could think of, either

```
res = join(unstack.(df, :household, :person, [:a, :b])..., on=:household)
names!(res, [:household, :a_1, :a_2, :b_1, :b_2])

```

or

```
tmp = melt(df, [:household, :person])
tmp[:variable] = string.(tmp[:variable], "_", tmp[:person])
res2 = unstack(tmp, :household, :variable, :value)

```