Source code for porespy.generators._borders

import numpy as np


__all__ = ['faces', 'borders']


[docs]def faces(shape, inlet=None, outlet=None): r""" Generate an image with ``True`` values on the specified ``inlet`` and ``outlet`` faces Parameters ---------- shape : list The ``[x, y, z (optional)]`` shape to generate. This will likely be obtained from ``im.shape`` where ``im`` is the image for which an array of faces is required. inlet : int The axis where the faces should be added (e.g. ``inlet=0`` will put ``True`` values on the ``x=0`` face). A value of ``None`` (default) bypasses the addition of inlets. outlet : int Same as ``inlet`` except for the outlet face. This is optional. It can be be applied at the same time as ``inlet``, instead of ``inlet`` (if ``inlet`` is set to ``None``), or ignored (if ``outlet = None``). Returns ------- faces : ndarray A boolean image of the given ``shape`` with ``True`` values on the specified ``inlet`` and/or ``outlet`` face(s). Examples -------- `Click here <https://porespy.org/examples/generators/reference/faces.html>`_ to view online example. """ im = np.zeros(shape, dtype=bool) # Parse inlet and outlet if inlet is not None: im = np.swapaxes(im, 0, inlet) im[0, ...] = True im = np.swapaxes(im, 0, inlet) if outlet is not None: im = np.swapaxes(im, 0, outlet) im[-1, ...] = True im = np.swapaxes(im, 0, outlet) if (inlet is None) and (outlet is None): raise Exception('Both inlet and outlet were given as None') return im
[docs]def borders(shape, thickness=1, mode='edges'): r""" Creates an array of specified size with corners, edges or faces labelled as ``True``. This can be used as mask to manipulate values laying on the perimeter of an image. Parameters ---------- shape : array_like The shape of the array to return. Can be either 2D or 3D. thickness : scalar (default is 1) The number of pixels/voxels layers to place along perimeter. mode : string The type of border to create. Options are 'faces', 'edges' (default) and 'corners'. In 2D 'corners' and 'edges' give the same result. Returns ------- image : ndarray An ndarray of specified shape with ``True`` values at the perimeter and ``False`` elsewhere Examples -------- `Click here <https://porespy.org/examples/generators/reference/borders.html>`_ to view online example. """ ndims = len(shape) t = thickness border = np.ones(shape, dtype=bool) if mode == 'faces': if ndims == 2: border[t:-t, t:-t] = False if ndims == 3: border[t:-t, t:-t, t:-t] = False elif mode == 'edges': if ndims == 2: border[t:-t, 0::] = False border[0::, t:-t] = False if ndims == 3: border[0::, t:-t, t:-t] = False border[t:-t, 0::, t:-t] = False border[t:-t, t:-t, 0::] = False elif mode == 'corners': if ndims == 2: border[t:-t, 0::] = False border[0::, t:-t] = False if ndims == 3: border[t:-t, 0::, 0::] = False border[0::, t:-t, 0::] = False border[0::, 0::, t:-t] = False return border