slope method

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

Slope identifies the steepness of the terrain at each location, expressed in positive degrees from 0 (flat) to 90. To express the result in percent rise, convert the slope angle in degrees using map algebra: Percent rise = 100 * tan(angle * pi/180). Percent rise will range from 0 to infinity, with a flat surface being 0 percent and a 45 degree surface being 100 percent.

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 slope of this function's field result.