Can anyone show me some sample codes of the following function?
func aggregated<Element, Result>( on columnNames: [String], naming: (String) -> String, transform: (DiscontiguousColumnSlice<Element>) throws -> Result? ) rethrows -> DataFrame
Can anyone show me some sample codes of the following function?
func aggregated<Element, Result>( on columnNames: [String], naming: (String) -> String, transform: (DiscontiguousColumnSlice<Element>) throws -> Result? ) rethrows -> DataFrame
Here is an example that computes the mean of the speed and weight columns using this method:
let means = dataFrame.grouped(by: "species").aggregated(
on: "speed", "weight",
naming: { "mean(\($0))" },
transform: { (slice: DiscontiguousColumnSlice<Double>) -> Double? in
slice.mean()
}
)