perturb method

List<num> perturb(List<num> position, List<num> deltaPosition)

Returns a random vector of length dimensions sampled from the interval obtained by intersecting this with the generalized rectangle centred at position with edge lengths (position - deltaPosition, position + deltaPosition).

Note: If the intersection along a certain interval is empty then the corrsponding coordinate is set to double.nan.

Throws an error of type ErrorOf<SearchSpace> if the length of the position or deltaPosition does not match dimensions.

Implementation

List<num> perturb(List<num> position, List<num> deltaPosition) {
  _updateCache();
  try {
    if (hasCustomOrder) {
      final result = List<num>.filled(dimensions, 0.0);
      for (var i in order) {
        result[i] = _intervals[i].perturb(position[i], deltaPosition[i]);
      }
      return result;
    } else {
      return List<num>.generate(dimensions,
          (i) => _intervals[i].perturb(position[i], deltaPosition[i]));
    }
  } on RangeError catch (_) {
    if (position.length != dimensions) {
      throw ErrorOf<SearchSpace>(
          message: 'Could not generate random point around $position.',
          invalidState:
              'Dimension mismatch: $dimensions != ${position.length}.',
          expectedState: 'The vector position must have length $dimensions.');
    }
    if (deltaPosition.length != dimensions) {
      throw ErrorOf<SearchSpace>(
          message:
              'Could not generate perturbation using magnitudes $deltaPosition.',
          invalidState:
              'Dimension mismatch: $dimensions != ${deltaPosition.length}.',
          expectedState:
              'The vector deltaPosition must have length $dimensions.');
    }
    rethrow;
  }
}