Class lsst::afw::math::LanczosFunction1

template<typename ReturnT>
class LanczosFunction1 : public lsst::afw::math::Function1<ReturnT>

1-dimensional Lanczos function

f(x) = sinc(pi x’) sinc(pi x’ / n) where x’ = x - xOffset and coefficient c0 = xOffset

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