sort method

Matrix sort({ List<int>? columnIndices, bool ascending = true, })

Sorts the matrix in ascending or descending order.

ascending: If true, sorts the matrix in ascending order; if false, sorts it in descending order (default is true).

Returns a new matrix with sorted values.

Example:

var matrix = Matrix([[3], [1], [4]]);
var sortedMatrix = matrix.sort(ascending: false);
print(sortedMatrix);
// Output:
// 4
// 3
// 1

Implementation

Matrix sort({List<int>? columnIndices, bool ascending = true}) {
  if (toList().isEmpty || this[0].isEmpty) {
    throw Exception('Matrix is empty');
  }

  Matrix sortedMatrix = Matrix([
    for (int i = 0; i < rowCount; i++)
      [for (int j = 0; j < columnCount; j++) this[i][j]]
  ]);

  // Sort all elements in ascending or descending order
  if (columnIndices == null || columnIndices.isEmpty) {
    List<dynamic> elements =
        sortedMatrix.toList().expand((row) => row).toList();

    elements.sort((a, b) => ascending ? a.compareTo(b) : b.compareTo(a));

    int k = 0;
    for (int i = 0; i < rowCount; i++) {
      for (int j = 0; j < columnCount; j++) {
        sortedMatrix[i][j] = elements[k++];
      }
    }
  } else {
    // Validate column indices
    for (int columnIndex in columnIndices) {
      if (columnIndex < 0 || columnIndex >= columnCount) {
        throw Exception('Invalid column index for sorting');
      }
    }

    sortedMatrix._data.sort((a, b) {
      for (int columnIndex in columnIndices) {
        int comparison = a[columnIndex].compareTo(b[columnIndex]);
        if (comparison != 0) {
          return ascending ? comparison : -comparison;
        }
      }
      return 0;
    });
  }

  return sortedMatrix;
}