landlab.components.lateral_erosion.node_finder

angle_finder(grid, dn, cn, rn)

Find the interior angle between two vectors on a grid.

Parameters:

• grid (ModelGrid) – A landlab grid.

• dn (int or array of int) – Node or nodes at the end of the first vector.

• cn (int or array of int) – Node or nodes at the vertex between vectors.

• rn (int or array of int) – Node or nodes at the end of the second vector.

Returns:

Angle between vectors (in radians).

Return type:

float or array of float

Examples

>>> import numpy as np
>>> from landlab import RasterModelGrid
>>> from landlab.components.lateral_erosion.node_finder import angle_finder

>>> grid = RasterModelGrid((3, 4))
>>> np.rad2deg(angle_finder(grid, 8, 5, 0))
90.0
>>> np.rad2deg(angle_finder(grid, (8, 9, 10, 6), 5, 6))
array([135.,  90.,  45.,   0.])

forty_five_node(donor, i, receiver, neighbors, diag_neigh)

ninety_node(donor, i, receiver, link_list, neighbors, diag_neigh)

node_finder(grid, i, flowdirs, drain_area)

Find lateral neighbor node of the primary node for straight, 45 degree, and 90 degree channel segments.

Parameters:

• grid (ModelGrid) – A Landlab grid object

• i (int) – node ID of primary node

• flowdirs (array) – Flow direction array

• drain_area (array) – drainage area array

Returns:

• lat_node (int) – node ID of lateral node

• radcurv_angle (float) – inverse radius of curvature of channel at lateral node

straight_node(donor, i, receiver, neighbors, diag_neigh)