Hello,
A dataset is
dataset = Dataset[{
<|"a" -> 1, "b" -> "x", "c" -> {1}|>,
<|"a" -> 2, "b" -> "y", "c" -> {2, 3}|>,
<|"a" -> 3, "b" -> "z", "c" -> {3}|>,
<|"a" -> 4, "b" -> "x", "c" -> {4, 5}|>,
<|"a" -> 5, "b" -> "y", "c" -> {5, 6, 7}|>,
<|"a" -> 6, "b" -> "z", "c" -> {}|>}]
Apply a function f to every element in every row:
dataset[All, All, f]
Partition the dataset based on a column, applying further operators to each group:
dataset[GroupBy["b"], Catenate, "c"]
If Dataset can accept three parameters, the first one is the operation on the row, how do we understand the second and third ones?
And, why does this not work
dataset[GroupBy["b"], "c"]
