Open huangyxi opened 8 months ago
Demonstrate how to aggregate over grouped array-like elements. (#3424)
julia> df = DataFrame(a=[1, 1, 2, 2], b=[[1, 2], [2, 3], [3, 4], [4, 5]]) 4×2 DataFrame Row │ a b │ Int64 Array… ─────┼─────────────── 1 │ 1 [1, 2] 2 │ 1 [2, 3] 3 │ 2 [3, 4] 4 │ 2 [4, 5] julia> gd = groupby(df, :a) GroupedDataFrame with 2 groups based on key: a First Group (2 rows): a = 1 Row │ a b │ Int64 Array… ─────┼─────────────── 1 │ 1 [1, 2] 2 │ 1 [2, 3] ⋮ Last Group (2 rows): a = 2 Row │ a b │ Int64 Array… ─────┼─────────────── 1 │ 2 [3, 4] 2 │ 2 [4, 5] julia> combine(gd, :b => Ref∘sum) 2×2 DataFrame Row │ a b_Ref_sum │ Int64 Array… ─────┼────────────────── 1 │ 1 [3, 5] 2 │ 2 [7, 9]
Demonstrate how to aggregate over grouped array-like elements. (#3424)