mapSeries<T, R> abstract method

DataFrame mapSeries<T, R>(
  1. R mapper(
    1. T value
    ), {
  2. int? index,
  3. String? name,
})

Returns a new DataFrame with a modified series according to the mapper function

index is an index of the series to be modified

name is a name of the series to be modified

index has precedence over name if both parameters are specified. At least one parameter must be specified! Otherwise, the method will throw an error

T is a type of the series source value, R is a type of the mapped value. If the value's type won't be changed, one needs to provide the same types for both generic types.

Usage example:

import 'package:ml_dataframe/ml_dataframe';

void main() {
  final data = DataFrame([
    ['col_1', 'col_2', 'col_3'],
    [      2,      20,     200],
    [      3,      30,     300],
    [      4,      40,     400],
  ]);
  final modifiedData = data.mapSeries<num, num>((value) => value * 2, name: 'col_2');

  print(modifiedData);
  // DataFrame (3 x 3)
  // col_1 col_2 col_3
  //     2    40   200
  //     3    60   300
  //     4    80   400
}

Implementation

DataFrame mapSeries<T, R>(R Function(T value) mapper,
    {int? index, String? name});