StarShaped#

class pinnx.geometry.StarShaped(center, radius, coeffs_cos, coeffs_sin)[source]#

Star-shaped 2d domain, i.e., a geometry whose boundary is parametrized in polar coordinates as:

\[ r(theta) := r_0 + sum_{i = 1}^N [a_i cos( i theta) + b_i sin(i theta) ], theta in [0,2 pi]. \]

For more details, refer to: Hiptmair et al. Large deformation shape uncertainty quantification in acoustic scattering. Adv Comp Math, 2018.

Parameters:
  • center – Center of the domain.

  • radius – 0th-order term of the parametrization (r_0).

  • coeffs_cos – i-th order coefficients for the i-th cos term (a_i).

  • coeffs_sin – i-th order coefficients for the i-th sin term (b_i).

boundary_normal(x)[source]#

Compute the unit normal at x for Neumann or Robin boundary conditions.

Parameters:

x – A 2D array of shape (n, dim), where n is the number of points and dim is the dimension of the geometry.

inside(x)[source]#

Check if x is inside the geometry (including the boundary).

Parameters:

x – A 2D array of shape (n, dim), where n is the number of points and dim is the dimension of the geometry.

Returns:

A boolean array of shape (n,) where each element is True if the point is inside the geometry.

on_boundary(x)[source]#

Check if x is on the geometry boundary.

Parameters:

x – A 2D array of shape (n, dim), where n is the number of points and dim is the dimension of the geometry.

Returns:

A boolean array of shape (n,) where each element is True if the point is on the boundary.

random_boundary_points(n, random='pseudo')[source]#

Compute the random point locations on the boundary.

random_points(n, random='pseudo')[source]#

Compute the random point locations in the geometry.

Parameters:
  • n – The number of points.

  • random – The random distribution. One of the following: “pseudo” (pseudorandom), “LHS” (Latin hypercube sampling), “Halton” (Halton sequence), “Hammersley” (Hammersley sequence), or “Sobol” (Sobol sequence

uniform_boundary_points(n)[source]#

Compute the equi-spaced point locations on the boundary.

Parameters:

n – The number of points.