d8_flow_direction

Signature

d8_flow_direction(elevation) → Field

Determine direction each cell drains towards

Parameters:

elevation (Field) – Floating point array

Returns:

New integral array

Description

Focal operation for determining the direction each cell drains towards. Directions are encoded by an integral number. Each number represents one of eight flow directions and the sink “direction”:

code	direction
7	north-west
8	north
9	north-east
4	west
5	sink
6	east
1	south-west
2	south
3	south-east

No-data handling

A cell containing a no-data value in the input array results in a no-data value in the corresponding output array. No new no-data values are generated.

Example

C

/* TODO */

C++

auto const flow_direction = lue::value_policies::d8_flow_direction<FlowDirectionElement>(elevation);

JAVA

// TODO

PYTHON

flow_direction = lfr.d8_flow_direction(elevation)