Dataset
Wolfram Kernel
Execution environment
Dataset[list_List | a_Association]
represents a structured dataset based on a hierarchy of lists and associations.
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Optimizations
Use numerical data or DateObject or boolean type for an entire column to get better performance.
Supported output forms
Examples
Basic examples
ds = Dataset[ Table[<|"a" -> 3 i, "b" -> 3 i + 2, "c" -> 3 i + 5|>, {i, 3}]]
Get the second row
ds[2]
Get the second column:
ds[All, "b"]
Compute the Total of each column:
ds[Total]
Load dataset of passengers
titanic = ExampleData[{"Dataset", "Titanic"}]
Get a random sample of passengers:
RandomSample[titanic, 5]
Count the number of passengers in 1st, 2nd and 3rd class:
titanic[Counts, "class"]
Get a histogram of passenger ages:
titanic[Histogram, "age"]
titanic[GroupBy["class"], Histogram[#, {0, 80, 4}] &, "age"]
Calculate the overall survival ratio:
ratio[list_] := list // Boole // Mean // N;
titanic[GroupBy["sex"], GroupBy["class"], ratio, "survived"]
Get dataset for training neural nets
ro = ResourceObject["Audio Cats and Dogs"];
data = ResourceData[ro];
classes = Normal[data[Union, "Label"]];
RandomSample[data, 2]
Notes
It supports lazy loading for a large set with many rows. The data is stored partially on Kernel if it exceeds 0.5 Mb.
The data is saved, when exported using Static HTML