Template Class LanczosFunction2

Inheritance Relationships

Base Type

Class Documentation

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.

Public Functions

LanczosFunction2(unsigned int n, double xOffset = 0.0, double yOffset = 0.0)

Parameters

  • n: order of Lanczos function

  • xOffset: x offset

  • yOffset: y offset

Construct a Lanczos function of specified order and x,y offset.

LanczosFunction2(LanczosFunction2 const&)
LanczosFunction2(LanczosFunction2&&)
LanczosFunction2 &operator=(LanczosFunction2 const&)
LanczosFunction2 &operator=(LanczosFunction2&&)
~LanczosFunction2()
std::shared_ptr<Function2<ReturnT>> clone() const

Return a pointer to a deep copy of this function

This function exists instead of a copy constructor so one can obtain a copy of an actual function instead of a useless copy of the base class.

Every non-virtual function must override this method.

Return

a pointer to a deep copy of the function

ReturnT operator()(double x, double y) const
unsigned int getOrder() const

Get the order of Lanczos function

std::string toString(std::string const&) const

Return a string representation of the function

Return

a string representation of the function

Protected Functions

LanczosFunction2()