withColumnNamesChanged method

DataFrame withColumnNamesChanged(Map<String, String> changes)

A new data frame with the column names changed.

Example:

print(iris.withHead(3));
print(iris.withHead(3).withColumnNamesChanged({
  "sepal_width": "sw",
  "petal_width": "pw",
}));

.--.------------.-----------.------------.-----------.--------.
|id|sepal_length|sepal_width|petal_length|petal_width|species |
:--+------------+-----------+------------+-----------+--------:
|1 |5.1         |3.5        |1.4         |0.2        |setosa  |
|2 |4.9         |3.0        |1.4         |0.2        |setosa  |
|3 |4.7         |3.2        |1.3         |0.2        |setosa  |
'--'------------'-----------'------------'-----------'--------'

.--.------------.---.------------.---.--------.
|id|sepal_length|sw |petal_length|pw |species |
:--+------------+---+------------+---+--------:
|1 |5.1         |3.5|1.4         |0.2|setosa  |
|2 |4.9         |3.0|1.4         |0.2|setosa  |
|3 |4.7         |3.2|1.3         |0.2|setosa  |
'--'------------'---'------------'---'--------'

Implementation

DataFrame withColumnNamesChanged(Map<String, String> changes) {
  final numericColumns = <String, NumericColumn>{},
      categoricColumns = <String, CategoricColumn>{};
  for (final MapEntry(:key, :value) in this.numericColumns.entries) {
    numericColumns[changes.containsKey(key) ? changes[key]! : key] =
        NumericColumn(value.values);
  }
  for (final MapEntry(:key, :value) in this.categoricColumns.entries) {
    categoricColumns[changes.containsKey(key) ? changes[key]! : key] =
        CategoricColumn(value.values);
  }
  return DataFrame(
    numericColumns: numericColumns,
    categoricColumns: categoricColumns,
  );
}