KazaiMazai / Koalas

Tabular data manipulation is Swift inspired by Pandas

Multidimensional data manipulation library in Swift

Features

• DataSeries, DataFrame, DataPanel for 1D, 2D, 3D data sets
• Missing data handling
• Automatic and explicit data alignment
• Memberwise arithmetic operations
• Flexible reshaping of data sets
• IO tools: read/write to csv, JSON encoding/decoding
• Data series-specific functionality: rolling and expanding window functions, shifting, conditional operations

Example

Define DataFrame

let df1 = DataFrame(dictionaryLiteral:
            ("1", DataSeries(repeating: 10.0, count: 10)),
            ("2", DataSeries(repeating: 20.0, count: 10)),
            ("3", DataSeries(repeating: 30.0, count: 10)),
            ("4", DataSeries(repeating: 40.0, count: 10)),
            ("5", DataSeries(repeating: 50.0, count: 10))
        )

1	2	3	4	5
10.0	20.0	30.0	40.0	50.0
10.0	20.0	30.0	40.0	50.0
10.0	20.0	30.0	40.0	50.0
10.0	20.0	30.0	40.0	50.0
10.0	20.0	30.0	40.0	50.0
10.0	20.0	30.0	40.0	50.0
10.0	20.0	30.0	40.0	50.0
10.0	20.0	30.0	40.0	50.0
10.0	20.0	30.0	40.0	50.0
10.0	20.0	30.0	40.0	50.0

Define const DataFrame with shape of existing:

let constDf = df1.mapTo(constant: 10.0)

Substract DataFrames memberwise:

let df2 = df1 - constDf      

1	2	3	4	5
0.0	10.0	20.0	30.0	40.0
0.0	10.0	20.0	30.0	40.0
0.0	10.0	20.0	30.0	40.0
0.0	10.0	20.0	30.0	40.0
0.0	10.0	20.0	30.0	40.0
0.0	10.0	20.0	30.0	40.0
0.0	10.0	20.0	30.0	40.0
0.0	10.0	20.0	30.0	40.0
0.0	10.0	20.0	30.0	40.0
0.0	10.0	20.0	30.0	40.0

Divide DataFrames memberwise:

let df3 = df1 / constDf

1	2	3	4	5
1.0	2.0	3.0	4.0	5.0
1.0	2.0	3.0	4.0	5.0
1.0	2.0	3.0	4.0	5.0
1.0	2.0	3.0	4.0	5.0
1.0	2.0	3.0	4.0	5.0
1.0	2.0	3.0	4.0	5.0
1.0	2.0	3.0	4.0	5.0
1.0	2.0	3.0	4.0	5.0
1.0	2.0	3.0	4.0	5.0
1.0	2.0	3.0	4.0	5.0

Calculate series-wise expanding sum:

let df4 = df3.expandingSum(initial: 0)

1	2	3	4	5
1.0	2.0	3.0	4.0	5.0
2.0	4.0	6.0	8.0	10.0
3.0	6.0	9.0	12.0	15.0
4.0	8.0	12.0	16.0	20.0
5.0	10.0	15.0	20.0	25.0
6.0	12.0	18.0	24.0	30.0
7.0	14.0	21.0	28.0	35.0
8.0	16.0	24.0	32.0	40.0
9.0	18.0	27.0	36.0	45.0
10.0	20.0	30.0	40.0	50.0

Shift DataFrame:

let df5 = df4.shiftedBy(5)

1	2	3	4	5
nil	nil	nil	nil	nil
nil	nil	nil	nil	nil
nil	nil	nil	nil	nil
nil	nil	nil	nil	nil
nil	nil	nil	nil	nil
1.0	2.0	3.0	4.0	5.0
2.0	4.0	6.0	8.0	10.0
3.0	6.0	9.0	12.0	15.0
4.0	8.0	12.0	16.0	20.0
5.0	10.0	15.0	20.0	25.0

Fill nils with backward filling:

let df6 = df5.fillNils(method: .backward(initial: nil))

1	2	3	4	5
1.0	2.0	3.0	4.0	5.0
1.0	2.0	3.0	4.0	5.0
1.0	2.0	3.0	4.0	5.0
1.0	2.0	3.0	4.0	5.0
1.0	2.0	3.0	4.0	5.0
1.0	2.0	3.0	4.0	5.0
2.0	4.0	6.0	8.0	10.0
3.0	6.0	9.0	12.0	15.0
4.0	8.0	12.0	16.0	20.0
5.0	10.0	15.0	20.0	25.0

Sum across columns, and turn result DataSeries into DataFrame of the initial shape:

let series1 = df6.columnSum()
let df7 = df6.mapTo(series: series1)

1	2	3	4	5
15.0	15.0	15.0	15.0	15.0
15.0	15.0	15.0	15.0	15.0
15.0	15.0	15.0	15.0	15.0
15.0	15.0	15.0	15.0	15.0
15.0	15.0	15.0	15.0	15.0
15.0	15.0	15.0	15.0	15.0
30.0	30.0	30.0	30.0	30.0
45.0	45.0	45.0	45.0	45.0
60.0	60.0	60.0	60.0	60.0
75.0	75.0	75.0	75.0	75.0

Installation:

Coming soon...

For more details check out the Docs:

Coming soon...

Licensing

Koalas is licensed under MIT license.