Gradients, fluxes, and divergences

Landlab is designed to easily calculate gradients in quantities across the grid, and to construct fluxes and flux divergences from them. Because these calculations tend to be a little more involved than property lookups, the methods tend to start with calc_.

Raster

calc_diff_at_d8	Calculate differences of node values over links and diagonals.
calc_diff_at_diagonal	Calculate differences of node values over diagonals.
calc_diff_at_link	Calculate differences in node_values at links.
calc_flux_div_at_cell	Calculate divergence of link-based fluxes at cells.
calc_flux_div_at_node	Calculate divergence of link-based fluxes at nodes.
calc_grad_across_cell_corners	grid.calc_grad_across_cell_corners(node_values, [cell_ids], out=None)
calc_grad_across_cell_faces	grid.calc_grad_across_cell_faces(node_values, [cell_ids], out=None)
calc_grad_along_node_links	grid.calc_grad_along_node_links(node_values, [cell_ids], out=None)
calc_grad_at_d8	Calculate gradients over all diagonals and links.
calc_grad_at_diagonal	Calculate gradients over all diagonals.
calc_grad_at_link	Calculate gradients in node_values at links.
calc_grad_at_patch	Calculate the components of the gradient of each raster patch.
calc_net_flux_at_node	Calculate net link fluxes at nodes.
calc_slope_at_cell_subtriangles	Calculate the slope (positive magnitude of gradient) at each of the eight cell subtriangles.
calc_slope_at_node	Array of slopes at nodes, averaged over neighboring patches.
calc_slope_at_patch	Calculate the slope (positive magnitude of gradient) at raster patches.
calc_unit_normal_at_patch	Calculate and return the unit normal vector <a, b, c> to a patch.
calc_unit_normals_at_cell_subtriangles	Calculate unit normals on a cell.
calc_unit_normals_at_patch_subtriangles	Calculate unit normals on a patch.
calculate_slope_aspect_at_nodes_burrough	Calculate topographic slope.

Hex

calc_diff_at_link	Calculate differences of node values over links.
calc_flux_div_at_cell	Calculate divergence of link-based fluxes at cells.
calc_flux_div_at_node	Calculate divergence of link-based fluxes at nodes.
calc_grad_at_link	Calculate gradients of node values at links.
calc_grad_at_patch	Calculate the components of the gradient at each patch.
calc_net_flux_at_node	Calculate net link fluxes at nodes.
calc_slope_at_node	Array of slopes at nodes, averaged over neighboring patches.
calc_slope_at_patch	Calculate the slope (positive magnitude of gradient) at patches.
calc_unit_normal_at_patch	Calculate and return the unit normal vector <a, b, c> to a patch.

Radial

calc_diff_at_link	Calculate differences of node values over links.
calc_flux_div_at_cell	Calculate divergence of link-based fluxes at cells.
calc_flux_div_at_node	Calculate divergence of link-based fluxes at nodes.
calc_grad_at_link	Calculate gradients of node values at links.
calc_grad_at_patch	Calculate the components of the gradient at each patch.
calc_net_flux_at_node	Calculate net link fluxes at nodes.
calc_slope_at_node	Array of slopes at nodes, averaged over neighboring patches.
calc_slope_at_patch	Calculate the slope (positive magnitude of gradient) at patches.
calc_unit_normal_at_patch	Calculate and return the unit normal vector <a, b, c> to a patch.

Voronoi

calc_diff_at_link	Calculate differences of node values over links.
calc_flux_div_at_cell	Calculate divergence of link-based fluxes at cells.
calc_flux_div_at_node	Calculate divergence of link-based fluxes at nodes.
calc_grad_at_link	Calculate gradients of node values at links.
calc_grad_at_patch	Calculate the components of the gradient at each patch.
calc_net_flux_at_node	Calculate net link fluxes at nodes.
calc_slope_at_node	Array of slopes at nodes, averaged over neighboring patches.
calc_slope_at_patch	Calculate the slope (positive magnitude of gradient) at patches.
calc_unit_normal_at_patch	Calculate and return the unit normal vector <a, b, c> to a patch.

FramedVoronoi

calc_diff_at_link	Calculate differences of node values over links.
calc_flux_div_at_cell	Calculate divergence of link-based fluxes at cells.
calc_flux_div_at_node	Calculate divergence of link-based fluxes at nodes.
calc_grad_at_link	Calculate gradients of node values at links.
calc_grad_at_patch	Calculate the components of the gradient at each patch.
calc_net_flux_at_node	Calculate net link fluxes at nodes.
calc_slope_at_node	Array of slopes at nodes, averaged over neighboring patches.
calc_slope_at_patch	Calculate the slope (positive magnitude of gradient) at patches.
calc_unit_normal_at_patch	Calculate and return the unit normal vector <a, b, c> to a patch.