desc.grid.LinearGrid

class desc.grid.LinearGrid(L=None, M=None, N=None, NFP=1, sym=False, axis=True, endpoint=False, rho=array(1.), theta=array(0.), zeta=array(0.))Source 

Grid in which the nodes are linearly spaced in each coordinate.

Useful for plotting and other analysis, though not very efficient for using as the solution grid.

Parameters:

L (int, optional) – Radial grid resolution.
M (int, optional) – Poloidal grid resolution.
N (int, optional) – Toroidal grid resolution.
NFP (int) – Number of field periods (Default = 1).
sym (bool) – True for stellarator symmetry, False otherwise (Default = False).
axis (bool) – True to include a point at rho=0 (default), False for rho[0] = rho[1]/2.
endpoint (bool) – If True, theta=0 and zeta=0 are duplicated after a full period. Should be False for use with FFT. (Default = False). This boolean is ignored if an array is given for theta or zeta.
rho (int or ndarray of float, optional) – Radial coordinates (Default = 1.0). Alternatively, the number of radial coordinates (if an integer). Note that if supplied the values may be reordered in the resulting grid.
theta (int or ndarray of float, optional) – Poloidal coordinates (Default = 0.0). Alternatively, the number of poloidal coordinates (if an integer). Note that if supplied the values may be reordered in the resulting grid.
zeta (int or ndarray of float, optional) – Toroidal coordinates (Default = 0.0). Alternatively, the number of toroidal coordinates (if an integer). Note that if supplied the values may be reordered in the resulting grid.

Methods

`change_resolution`(L, M, N[, NFP])	Change the resolution of the grid.
`compress`(x[, surface_label])	Return elements of `x` at indices of unique surface label values.
`copy`([deepcopy])	Return a (deep)copy of this object.
`copy_data_from_other`(x, other_grid[, ...])	Copy data x from other_grid to this grid at matching surface label.
`equiv`(other)	Compare equivalence between DESC objects.
`expand`(x[, surface_label])	Expand `x` by duplicating elements to match the grid's pattern.
`get_label`(label)	Get general label that specifies direction given label.
`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.
`coordinates`	Coordinates specified by the nodes.
`endpoint`	Whether the grid is made of open or closed intervals.
`inverse_alpha_idx`	Indices that recover field line poloidal angles.
`inverse_poloidal_idx`	Indices that recover the unique poloidal coordinates.
`inverse_rho_idx`	Indices of unique_rho_idx that recover the rho coordinates.
`inverse_theta_PEST_idx`	Indices that recover unique straight field line poloidal angles.
`inverse_theta_idx`	Indices that recover unique theta coordinates.
`inverse_zeta_idx`	Indices of unique_zeta_idx that recover the zeta coordinates.
`is_meshgrid`	Whether this grid is a tensor-product grid.
`node_pattern`	Pattern for placement of nodes in (rho,theta,zeta).
`nodes`	Node coordinates, in (rho,theta,zeta).
`num_alpha`	Number of unique field line poloidal angles.
`num_nodes`	Total number of nodes.
`num_poloidal`	Number of unique poloidal angle coordinates.
`num_rho`	Number of unique rho coordinates.
`num_theta`	Number of unique theta coordinates.
`num_theta_PEST`	Number of unique straight field line poloidal angles.
`num_zeta`	Number of unique zeta coordinates.
`period`	Periodicity of coordinates.
`spacing`	Quadrature weights for integration over surfaces.
`sym`	True for stellarator symmetry, False otherwise.
`unique_alpha_idx`	Indices of unique field line poloidal angles.
`unique_poloidal_idx`	Indices of unique poloidal angle coordinates.
`unique_rho_idx`	Indices of unique rho coordinates.
`unique_theta_PEST_idx`	Indices of unique straight field line poloidal angles.
`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.