Class lsst::afw::math::LanczosFunction2

template<typename ReturnT>
class LanczosFunction2 : public lsst::afw::math::Function2<ReturnT>

2-dimensional separable Lanczos function

f(x, y) = sinc(pi x’) sinc(pi x’ / n) sinc(pi y’) sinc(pi y’ / n) where x’ = x - xOffset and y’ = y - yOffset and coefficients c0 = xOffset, c1 = yOffset

Warning

the Lanczos function is sometimes forced to 0 if |x’| > n or |y’| > n but this implementation does not perform that truncation so as to improve Lanczos kernels.