Syntax

   @RasterSlope([REJECTABLE], <output type>[, <interpolate nodata>[, <algorithm>]])

Arguments

   REJECTABLE

      Specifies if the function will supply a rejection code and message
      to the invalid feature and output it to the rejected port, or will
      fail upon being supplied invalid features.

      A feature can be rejected for the following reasons:
         - The feature has invalid geometry
         - The raster's slope cannot be calculated

   <output type>

      Specifies the measurement units of the output slope data.

      When set to 'Degrees', the slope will be calculated in degrees.
      Values range from 0 to 90.

      When set to The 'PercentRise', the slope will be calculated as percent
      rise. Values range from 0 to infinity. A flat surface will have a slope
      of 0 percent, a 45 degree surface will have a slope of 100 percent, and
      as the surface becomes more vertical the slope gets progressively larger.

      Range: Degrees | PercentRise

   <interpolate nodata>

      Whether to calculate values at raster edges and near nodata values.

      When this is set to 'DoNotInterpolateNodata', there will be a one pixel
      border around the edge of the raster set to the nodata value.
      Additionally, when any pixel in the 3x3 window used to calculate the
      slope value is equal to nodata, the output pixel will also be set to
      nodata. If the input band does not have a nodata value, the output band
      nodata value will be set to -1.

      When this is set to 'InterpolateNodata', values around the edge and near
      nodata values will be estimated by interpolating missing values.

      Range: InterpolateNodata | DoNotInterpolateNodata

   <algorithm>

      The algorithm used to calculate slope.

      Some analyses have suggested that Horn's formula is better suited to
      rougher terrain, whereas Zevenbergen & Thorne's formula is better for
      smooth terrain.

      Range: Horn | ZevenbergenThorne

Description

   The @RasterSlope function calculates the slope (maximum rate of change in z)
   for each cell of a raster.

   Each selected input band will be converted to a REAL64 band with output
   values dependent on the <output type>.

   Note that the horizontal and vertical units are expected to be equal.
   If this is not the case, @Scale may be used prior to this function to
   apply an appropriate scale factor.

   This function supports raster band selection. @SelectRaster can be used
   to modify selection.