field_map_loaders module

Define functions to load field maps.

warn_norm(path, norm)[source]

Raise this warning only once.

Parameters:

field_1d(path)[source]

Load a 1D field.

Parameters:

path (pathlib.Path) – The path to the file to load.

Return type:

tuple[int, float, float, ndarray, int]

Returns:

n_z (int) – Number of steps in the array.
zmax (float) – z position of the filemap end.
norm (float) – Electric field normalisation factor. It is different from k_e (6th argument of the FIELD_MAP command). Electric fields are normalised by k_e/norm, hence norm should be unity by default.
f_z (numpy.ndarray) – Array holding field. If electric, will be in \(\mathrm{MV/m}\).
n_cell (int) – Number of cells in the cavity.

field_3d(path)[source]

Load a 3D field.

Parameters:

path (pathlib.Path) – The path to the file to load.

Return type:

Returns:

n_z (int) – Number of steps along the z-axis.
zmax (float) – Maximum z position.
n_x (int) – Number of steps along the x-axis.
xmin (float) – Minimum x position.
xmax (float) – Maximum x position.
n_y (int) – Number of steps along the y-axis.
ymin (float) – Minimum y position.
ymax (float) – Maximum y position.
norm (float) – Field normalization factor.
field (numpy.ndarray) – 3D array holding field values. If electric, will be in \(\mathrm{MV/m}\).

_get_number_of_cells(f_z)[source]

Count number of times the array of z-electric field changes sign.

See SO.