aspect method

Composes a function that returns the aspect of this function's field result across its extent.

Aspect identifies the compass direction that the downhill slope faces at each location.

It is expressed in positive degrees from 0 up to but not including 360, measured clockwise from the positive Y axis.

Flat terrain is given an aspect of -1.

The slope and aspect functions require that input data is in a shape-preserving (conformal) projected coordinate system, and that the data's vertical (elevation) units match the horizontal units of that coordinate system.

The function result has no data where this function's field result has no data.

The function result extent equals that of this function's field result.

Return Value: A function that returns the aspect of this function's field result.