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_`.
 `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 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.
 `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 to a patch.
 `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 to a patch.
 `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 to a patch.
 `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 to a patch.