helpers.transfer_helper module

border_padding(grid, l, r, pad_type='mirror')

Function to pad/embed an array at the boundaries

Parameters:

• grid (np.npdarray) – the input array

• l – left boundary

• r – right boundary

• pad_type – type of padding

Returns:

the padded array

Return type:

np.npdarray

continue_periodic_array(arr, nn)

Function to append an array for nn neighbors for periodicity

Parameters:

• arr (np.ndarray) – the input array

• nn (list) – the neighbors

Returns:

the continued array

Return type:

np.ndarray

interpolation_matrix_1d(fine_grid, coarse_grid, k=2, periodic=False, pad=1, equidist_nested=True)

Function to contruct the restriction matrix in 1d using barycentric interpolation

Parameters:

• fine_grid (np.ndarray) – a one dimensional 1d array containing the nodes of the fine grid

• coarse_grid (np.ndarray) – a one dimensional 1d array containing the nodes of the coarse grid

• k (int) – order of the restriction

• periodic (bool) – flag to indicate periodicity

• pad (int) – padding parameter for boundaries

• equidist_nested (bool) – shortcut possible, if nodes are equidistant and nested

Returns:

interpolation matrix

Return type:

sprs.csc_matrix

next_neighbors(p, ps, k)

Function to find the next neighbors for a non-periodic setup

This function gives for a value p the k points next to it which are found in in the vector ps

Parameters:

• p – the current point

• ps (np.ndarray) – the grid with the potential neighbors

• k (int) – number of neighbors to find

Returns:

the k next neighbors

Return type:

list

next_neighbors_periodic(p, ps, k)

Function to find the next neighbors for a periodic setup

This function gives for a value p the k points next to it which are found in in the vector ps and the points which are found periodically.

Parameters:

• p – the current point

• ps (np.ndarray) – the grid with the potential neighbors

• k (int) – number of neighbors to find

Returns:

the k next neighbors

Return type:

list

restriction_matrix_1d(fine_grid, coarse_grid, k=2, periodic=False, pad=1)

Function to contruct the restriction matrix in 1d using barycentric interpolation

Parameters:

• fine_grid (np.ndarray) – a one dimensional 1d array containing the nodes of the fine grid

• coarse_grid (np.ndarray) – a one dimensional 1d array containing the nodes of the coarse grid

• k (int) – order of the restriction

• periodic (bool) – flag to indicate periodicity

• pad (int) – padding parameter for boundaries

Returns:

restriction matrix

Return type:

sprs.csc_matrix