extract_oversampled

extract_oversampled(a, xf, yf, kernel_oversampling, kernelwidth)

Extract the (xf-th,yf-th) w-kernel from the oversampled parent

Offsets are suitable for correcting of fractional coordinates, e.g. an offset of (xf,yf) results in the kernel for an (-xf,-yf) sub-grid offset.

We do not want to make assumptions about the source grid’s symmetry here, which means that the grid’s side length must be at least kernel_oversampling*(npixel+2) to contain enough information in all circumstances

Parameters

• xf –

• yf –

• a – grid from which to extract

• kernel_oversampling – oversampling factor

• kernelwidth – size of section