landlab.grid.unstructured.base¶

class BaseGrid[source]¶

Bases: object

__init__([coord0, coord1, …], axis_name=None, axis_units=None)

Parameters:

coord0 (sequence of array-like) – Coordinates of grid nodes
coord1 (sequence of array-like) – Coordinates of grid nodes
... (sequence of array-like) – Coordinates of grid nodes
axis_name (sequence of strings, optional) – Names of coordinate axes
axis_units (sequence of strings, optional) – Units of coordinate axes

Returns:

A newly-created BaseGrid

Return type:

BaseGrid

Examples

>>> from landlab.grid.unstructured.base import BaseGrid
>>> ngrid = BaseGrid(([0, 0, 1, 1], [0, 1, 0, 1]))
>>> ngrid.number_of_nodes
4
>>> ngrid.x_at_node
array([0.,  1.,  0.,  1.])
>>> ngrid.x_at_node[2]
0.0
>>> ngrid.point_at_node[2]
array([1.,  0.])
>>> ngrid.coord_at_node[:, [2, 3]]
array([[1.,  1.],
       [0.,  1.]])

>>> cells = ([0, 1, 2, 1, 3, 2], [3, 3], [0, 1])
>>> ngrid = BaseGrid(([0, 0, 1, 1], [0, 1, 0, 1]), cells=cells)
>>> ngrid.number_of_cells
2
>>> ngrid.node_at_cell
array([0, 1])

>>> links = [(0, 2), (1, 3), (0, 1), (1, 2), (0, 3)]
>>> ngrid = BaseGrid(([0, 0, 1, 1], [0, 1, 0, 1]), links=zip(*links))
>>> ngrid.number_of_links
5
>>> ngrid.links_leaving_at_node(0)
array([0, 2, 4])
>>> len(ngrid.links_entering_at_node(0)) == 0
True

>>> tails, heads = zip(*links)
>>> grid = BaseGrid(
...     ([0, 0, 1, 1], [0, 1, 0, 1]), node_status=[0, 0, 0, 4], links=[tails, heads]
... )
>>> grid.status_at_node
array([0, 0, 0, 4])
>>> len(grid.active_links_entering_at_node(0)) == 0
True
>>> grid.active_links_leaving_at_node(0)
array([0, 2])

__init__([coord0, coord1, …], axis_name=None, axis_units=None)

Parameters:

coord0 (sequence of array-like) – Coordinates of grid nodes
coord1 (sequence of array-like) – Coordinates of grid nodes
... (sequence of array-like) – Coordinates of grid nodes
axis_name (sequence of strings, optional) – Names of coordinate axes
axis_units (sequence of strings, optional) – Units of coordinate axes

Returns:

A newly-created BaseGrid

Return type:

BaseGrid

Examples

>>> from landlab.grid.unstructured.base import BaseGrid
>>> ngrid = BaseGrid(([0, 0, 1, 1], [0, 1, 0, 1]))
>>> ngrid.number_of_nodes
4
>>> ngrid.x_at_node
array([0.,  1.,  0.,  1.])
>>> ngrid.x_at_node[2]
0.0
>>> ngrid.point_at_node[2]
array([1.,  0.])
>>> ngrid.coord_at_node[:, [2, 3]]
array([[1.,  1.],
       [0.,  1.]])

>>> cells = ([0, 1, 2, 1, 3, 2], [3, 3], [0, 1])
>>> ngrid = BaseGrid(([0, 0, 1, 1], [0, 1, 0, 1]), cells=cells)
>>> ngrid.number_of_cells
2
>>> ngrid.node_at_cell
array([0, 1])

>>> links = [(0, 2), (1, 3), (0, 1), (1, 2), (0, 3)]
>>> ngrid = BaseGrid(([0, 0, 1, 1], [0, 1, 0, 1]), links=zip(*links))
>>> ngrid.number_of_links
5
>>> ngrid.links_leaving_at_node(0)
array([0, 2, 4])
>>> len(ngrid.links_entering_at_node(0)) == 0
True

>>> tails, heads = zip(*links)
>>> grid = BaseGrid(
...     ([0, 0, 1, 1], [0, 1, 0, 1]),
...     node_status=[0, 0, 0, 4],
...     links=[tails, heads],
... )
>>> grid.status_at_node
array([0, 0, 0, 4])
>>> len(grid.active_links_entering_at_node(0)) == 0
True
>>> grid.active_links_leaving_at_node(0)
array([0, 2])

__init__([coord0, coord1, ..., ]axis_name=None, axis_units=None)[source]¶

Parameters:

coord0 (sequence of array-like) – Coordinates of grid nodes
coord1 (sequence of array-like) – Coordinates of grid nodes
... (sequence of array-like) – Coordinates of grid nodes
axis_name (sequence of strings, optional) – Names of coordinate axes
axis_units (sequence of strings, optional) – Units of coordinate axes

Returns:

A newly-created BaseGrid

Return type:

BaseGrid

Examples

>>> from landlab.grid.unstructured.base import BaseGrid
>>> ngrid = BaseGrid(([0, 0, 1, 1], [0, 1, 0, 1]))
>>> ngrid.number_of_nodes
4
>>> ngrid.x_at_node
array([0.,  1.,  0.,  1.])
>>> ngrid.x_at_node[2]
0.0
>>> ngrid.point_at_node[2]
array([1.,  0.])
>>> ngrid.coord_at_node[:, [2, 3]]
array([[1.,  1.],
       [0.,  1.]])

>>> cells = ([0, 1, 2, 1, 3, 2], [3, 3], [0, 1])
>>> ngrid = BaseGrid(([0, 0, 1, 1], [0, 1, 0, 1]), cells=cells)
>>> ngrid.number_of_cells
2
>>> ngrid.node_at_cell
array([0, 1])

>>> links = [(0, 2), (1, 3), (0, 1), (1, 2), (0, 3)]
>>> ngrid = BaseGrid(([0, 0, 1, 1], [0, 1, 0, 1]), links=zip(*links))
>>> ngrid.number_of_links
5
>>> ngrid.links_leaving_at_node(0)
array([0, 2, 4])
>>> len(ngrid.links_entering_at_node(0)) == 0
True

>>> tails, heads = zip(*links)
>>> grid = BaseGrid(
...     ([0, 0, 1, 1], [0, 1, 0, 1]),
...     node_status=[0, 0, 0, 4],
...     links=[tails, heads],
... )
>>> grid.status_at_node
array([0, 0, 0, 4])
>>> len(grid.active_links_entering_at_node(0)) == 0
True
>>> grid.active_links_leaving_at_node(0)
array([0, 2])

__new__(**kwargs)¶

active_links()[source]¶

active_links_entering_at_node(node)[source]¶

active_links_leaving_at_node(node)[source]¶

active_nodes()[source]¶

property axis_name¶

Name of each axis.

Returns:: Names of each axis.
Return type:: tuple of strings

Examples

>>> from landlab.grid.unstructured.base import BaseGrid
>>> ngrid = BaseGrid(([0, 1, 0], [1, 1, 0]))
>>> ngrid.axis_name
('y', 'x')

>>> ngrid = BaseGrid(([0, 1, 0], [1, 1, 0]), axis_name=["lat", "lon"])
>>> ngrid.axis_name
('lat', 'lon')

property axis_units¶

Coordinate units of each axis.

Returns:: Coordinate units of each axis.
Return type:: tuple of strings

Examples

>>> from landlab.grid.unstructured.base import BaseGrid
>>> ngrid = BaseGrid(([0, 1, 0], [1, 1, 0]))
>>> ngrid.axis_units
('-', '-')

>>> ngrid = BaseGrid(
...     ([0, 1, 0], [1, 1, 0]), axis_units=["degrees_north", "degrees_east"]
... )
>>> ngrid.axis_units
('degrees_north', 'degrees_east')

boundary_nodes()[source]¶

property cell_at_node¶

closed_boundary_nodes()[source]¶

property coord_at_node¶

core_cells()[source]¶

core_nodes()[source]¶

static create_active_link_grid(node_status, links, number_of_nodes)[source]¶

fixed_gradient_boundary_nodes()[source]¶

fixed_value_boundary_nodes()[source]¶

length_of_link(link=None)[source]¶

Length of grid links.

Parameters:: link (array-like, optional) – Link IDs

Examples

>>> from landlab.grid.unstructured.base import BaseGrid
>>> links = [(0, 2), (1, 3), (0, 1), (2, 3), (0, 3)]
>>> grid = BaseGrid(([0, 0, 4, 4], [0, 3, 0, 3]), links=links)
>>> grid.length_of_link()
array([4.,  4.,  3.,  3.,  5.])
>>> grid.length_of_link(0)
array([4.])

>>> grid.length_of_link().min()
3.0
>>> grid.length_of_link().max()
5.0

links_entering_at_node(node)[source]¶

links_leaving_at_node(node)[source]¶

property ndim¶

property node_at_cell¶

property node_at_link_end¶

property node_at_link_start¶

node_to_node_distance(node0, node1, out=None)[source]¶

Distance between nodes.

Parameters:

node0 (array-like) – Node ID of start
node1 (array-like) – Node ID of end

Returns:

Distances between nodes.

Return type:

array

Examples

>>> from landlab.grid.unstructured.base import BaseGrid
>>> grid = BaseGrid(([0, 0, 4, 4], [0, 3, 0, 3]))
>>> grid.node_to_node_distance(0, 3)
array([5.])
>>> grid.node_to_node_distance(0, [0, 1, 2, 3])
array([0.,  3.,  4.,  5.])

property number_of_cells¶: Number of cells.

property number_of_links¶: Number of links.

property number_of_nodes¶: Number of nodes.

property point_at_node¶

point_to_node_angle(point, node=None, out=None)[source]¶

Angle from a point to a node.

Parameters:

point (tuple) – Coordinates of point
node (array-like) – Node IDs

Returns:

Angles from point to node as radians.

Return type:

array

Examples

>>> from landlab.grid.unstructured.base import BaseGrid
>>> grid = BaseGrid(([0, 0, 1, 1], [0, 1, 0, 1]))
>>> grid.point_to_node_angle((0.0, 0.0), [1, 2, 3]) / np.pi
array([0.  ,  0.5 ,  0.25])
>>> grid.point_to_node_angle((0.0, 0.0)) / np.pi
array([0.  ,  0.  ,  0.5 ,  0.25])
>>> out = np.empty(4)
>>> out is grid.point_to_node_angle((0.0, 0.0), out=out)
True
>>> out / np.pi
array([0.  ,  0.  ,  0.5 ,  0.25])

point_to_node_azimuth(point, node=None, out=None)[source]¶

Azimuth from a point to a node.

Parameters:

point (tuple) – Coordinates of point
node (array-like) – Node IDs

Returns:

Azimuths from point to node.

Return type:

array

Examples

>>> from landlab.grid.unstructured.base import BaseGrid
>>> grid = BaseGrid(([0, 0, 1, 1], [0, 1, 0, 1]))
>>> grid.point_to_node_azimuth((0.0, 0.0), [1, 2, 3])
array([90.,   0.,  45.])
>>> grid.point_to_node_azimuth((0.0, 0.0))
array([90.,  90.,   0.,  45.])
>>> grid.point_to_node_azimuth((0.0, 0.0), 1)
array([90.])
>>> out = np.empty(4)
>>> out is grid.point_to_node_azimuth((0.0, 0.0), out=out)
True
>>> out
array([90.,  90.,   0.,  45.])

point_to_node_distance(point, node=None, out=None)[source]¶

Distance from a point to a node.

Parameters:

point (tuple) – Coordinates of point
node (array-like) – Node IDs

Returns:

Distances from point to node.

Return type:

array

Examples

>>> from landlab.grid.unstructured.base import BaseGrid
>>> grid = BaseGrid(([0, 0, 4, 4], [0, 3, 0, 3]))
>>> grid.point_to_node_distance((0.0, 0.0), [1, 2, 3])
array([3.,  4.,  5.])
>>> grid.point_to_node_distance((0.0, 0.0))
array([0.,  3.,  4.,  5.])
>>> out = np.empty(4)
>>> out is grid.point_to_node_distance((0.0, 0.0), out=out)
True
>>> out
array([0.,  3.,  4.,  5.])

point_to_node_vector(point, node=None, out=None)[source]¶

Azimuth from a point to a node.

Parameters:

point (tuple) – Coordinates of point
node (array-like) – Node IDs

Returns:

Vector from point to node.

Return type:

array

Examples

>>> from landlab.grid.unstructured.base import BaseGrid
>>> grid = BaseGrid(([0, 0, 1, 1], [0, 1, 0, 1]))
>>> grid.point_to_node_vector((0.0, 0.0), [1, 2, 3])
array([[0.,  1.,  1.],
       [1.,  0.,  1.]])
>>> grid.point_to_node_vector((0.0, 0.0))
array([[0.,  0.,  1.,  1.],
       [0.,  1.,  0.,  1.]])
>>> grid.point_to_node_vector((0.0, 0.0), 1)
array([[0.],
       [1.]])
>>> out = np.empty((2, 1))
>>> out is grid.point_to_node_vector((0.0, 0.0), 1, out=out)
True
>>> out
array([[0.],
       [1.]])

property status_at_node¶

property x_at_node¶

property y_at_node¶

point_to_point_angle(point0, point1, out=None)[source]¶

Angle of vector that joins two points.

Parameters:

(y0 (tuple of array_like)
x0) (tuple of array_like)
(y1 (tuple of array_like)
x1) (tuple of array_like)
out (array_like, optional) – An array to store the output. Must be the same shape as the output would have.

Returns:

a – Angle of vector joining points; if out is provided, v will be equal to out.

Return type:

array_like

point_to_point_azimuth(point0, point1, out=None)[source]¶

Azimuth of vector that joins two points.

Parameters:

(y0 (tuple of array_like)
x0) (tuple of array_like)
(y1 (tuple of array_like)
x1) (tuple of array_like)
out (array_like, optional) – An array to store the output. Must be the same shape as the output would have.

Returns:

azimuth – Azimuth of vector joining points; if out is provided, v will be equal to out.

Return type:

array_like

Examples

>>> from landlab.grid.unstructured.base import point_to_point_azimuth
>>> point_to_point_azimuth((0, 0), (1, 0))
array([0.])
>>> point_to_point_azimuth([(0, 1), (0, 1)], (1, 0))
array([ 0., -90.])
>>> point_to_point_azimuth([(0, 1, 0), (0, 1, 2)], [(1, 1, 2), (0, 0, 4)])
array([ 0., -90.,  45.])

point_to_point_distance(point0, point1, out=None)[source]¶

Length of vector that joins two points.

Parameters:

(y0 (tuple of array_like)
x0) (tuple of array_like)
(y1 (tuple of array_like)
x1) (tuple of array_like)
out (array_like, optional) – An array to store the output. Must be the same shape as the output would have.

Returns:

l – Length of vector joining points; if out is provided, v will be equal to out.

Return type:

array_like

Examples

>>> from landlab.grid.unstructured.base import point_to_point_distance
>>> point_to_point_distance((0, 0), (3, 4))
array([5.])
>>> point_to_point_distance((0, 0), ([3, 6], [4, 8]))
array([ 5.,  10.])

point_to_point_vector(point0, point1, out=None)[source]¶

Vector that joins two points.

Parameters:

(y0 (tuple of array_like)
x0) (tuple of array_like)
(y1 (tuple of array_like)
x1) (tuple of array_like)
out (array_like, optional) – An array to store the output. Must be the same shape as the output would have.

Returns:

(dy, dx) – Vectors between points; if out is provided, v will be equal to out.

Return type:

tuple of array_like

Examples

>>> from landlab.grid.unstructured.base import point_to_point_vector
>>> point_to_point_vector((0, 0), (1, 2))
array([[1],
       [2]])
>>> point_to_point_vector([(0, 1), (0, 1)], (1, 2))
array([[1, 0],
       [2, 1]])
>>> point_to_point_vector([(0, 0, 0), (0, 1, 2)], [(1, 2, 2), (2, 4, 4)])
array([[1, 2, 2],
       [2, 3, 2]])