openmc.Region

class openmc.Region

Region of space that can be assigned to a cell.

Region is an abstract base class that is inherited by openmc.Halfspace, openmc.Intersection, openmc.Union, and openmc.Complement. Each of those respective classes are typically not instantiated directly but rather are created through operators of the Surface and Region classes.

clone(memo=None)

Create a copy of this region - each of the surfaces in the region’s nodes will be cloned and will have new unique IDs.

Parameters

memo (dict or None) – A nested dictionary of previously cloned objects. This parameter is used internally and should not be specified by the user.

Returns

clone – The clone of this region

Return type

openmc.Region

static from_expression(expression, surfaces)

Generate a region given an infix expression.

Parameters

• expression (str) – Boolean expression relating surface half-spaces. The possible operators are union ‘|’, intersection ‘ ‘, and complement ‘~’. For example, ‘(1 -2) | 3 ~(4 -5)’.

• surfaces (dict) – Dictionary whose keys are surface IDs that appear in the Boolean expression and whose values are Surface objects.

get_surfaces(surfaces=None)

Recursively find all surfaces referenced by a region and return them

Parameters

surfaces (dict, optional) – Dictionary mapping surface IDs to openmc.Surface instances

Returns

surfaces – Dictionary mapping surface IDs to openmc.Surface instances

Return type

dict

remove_redundant_surfaces(redundant_surfaces)

Recursively remove all redundant surfaces referenced by this region

New in version 0.12.

Parameters

redundant_surfaces (dict) – Dictionary mapping redundant surface IDs to class:openmc.Surface instances that should replace them.

rotate(rotation, pivot=(0.0, 0.0, 0.0), order='xyz', inplace=False, memo=None)

Rotate surface by angles provided or by applying matrix directly.

New in version 0.12.

Parameters

• rotation (3-tuple of float, or 3x3 iterable) – A 3-tuple of angles \((\phi, \theta, \psi)\) in degrees where the first element is the rotation about the x-axis in the fixed laboratory frame, the second element is the rotation about the y-axis in the fixed laboratory frame, and the third element is the rotation about the z-axis in the fixed laboratory frame. The rotations are active rotations. Additionally a 3x3 rotation matrix can be specified directly either as a nested iterable or array.

• pivot (iterable of float, optional) – (x, y, z) coordinates for the point to rotate about. Defaults to (0., 0., 0.)

• order (str, optional) – A string of ‘x’, ‘y’, and ‘z’ in some order specifying which rotation to perform first, second, and third. Defaults to ‘xyz’ which means, the rotation by angle \(\phi\) about x will be applied first, followed by \(\theta\) about y and then \(\psi\) about z. This corresponds to an x-y-z extrinsic rotation as well as a z-y’-x’’ intrinsic rotation using Tait-Bryan angles \((\phi, \theta, \psi)\).

• inplace (bool) – Whether or not to return a new instance of Surface or to modify the coefficients of this Surface in place. Defaults to False.

• memo (dict or None) – Dictionary used for memoization

Returns

Translated region

Return type

openmc.Region

translate(vector, inplace=False, memo=None)

Translate region in given direction

Parameters

• vector (iterable of float) – Direction in which region should be translated

• inplace (bool) –

  Whether or not to return a region based on new surfaces or one based on the original surfaces that have been modified.

  New in version 0.13.1.

• memo (dict or None) – Dictionary used for memoization. This parameter is used internally and should not be specified by the user.

Returns

Translated region

Return type

openmc.Region