Linear focal op with an explicit kernel (differentiable).

The kernel is a (2r+1) x (2r+1) matrix of weights; the op is the weighted sum over the window. Unlike focal() with an arbitrary fn, a kernel focal is differentiable with respect to its weights: pass the returned LazyRaster as wrt to lazy_value_and_grad().

Usage

focal_kernel(x, weights, boundary = "nodata")

Arguments

x

A LazyRaster.

weights

Square odd-sided numeric matrix, rows = dy, cols = dx.

boundary

Boundary policy; only "nodata" in v1.

Value

A LazyRaster.