desc.grid.Grid

class desc.grid.Grid(nodes, sort=False, jitable=False)Source

Collocation grid with custom node placement.

Unlike subclasses LinearGrid and ConcentricGrid, the base Grid allows the user to pass in a custom set of collocation nodes.

Parameters:

• nodes (ndarray of float, size(num_nodes,3)) – Node coordinates, in (rho,theta,zeta)

• sort (bool) – Whether to sort the nodes for use with FFT method.

• jitable (bool) – Whether to skip certain checks and conditionals that don’t work under jit. Allows grid to be created on the fly with custom nodes, but weights, symmetry etc may be wrong if grid contains duplicate nodes.

Methods

compress(x[, surface_label])	Return elements of x at indices of unique surface label values.
copy([deepcopy])	Return a (deep)copy of this object.
equiv(other)	Compare equivalence between DESC objects.
expand(x[, surface_label])	Expand x by duplicating elements to match the grid's pattern.
load(load_from[, file_format])	Initialize from file.
replace_at_axis(x, y[, copy])	Replace elements of x with elements of y at the axis of grid.
save(file_name[, file_format, file_mode])	Save the object.

Attributes

L	Radial grid resolution.
M	Poloidal grid resolution.
N	Toroidal grid resolution.
NFP	Number of (toroidal) field periods.
axis	Indices of nodes at magnetic axis.
inverse_rho_idx	Indices of unique_rho_idx that recover the rho coordinates.
inverse_theta_idx	Indices of unique_theta_idx that recover the theta coordinates.
inverse_zeta_idx	Indices of unique_zeta_idx that recover the zeta coordinates.
node_pattern	Pattern for placement of nodes in (rho,theta,zeta).
nodes	Node coordinates, in (rho,theta,zeta).
num_nodes	Total number of nodes.
num_rho	Number of unique rho coordinates.
num_theta	Number of unique theta coordinates.
num_zeta	Number of unique zeta coordinates.
spacing	Node spacing, in (rho,theta,zeta).
sym	True for stellarator symmetry, False otherwise.
unique_rho_idx	Indices of unique rho coordinates.
unique_theta_idx	Indices of unique theta coordinates.
unique_zeta_idx	Indices of unique zeta coordinates.
weights	Weight for each node, either exact quadrature or volume based.