Template Class LanczosFunction1

Inheritance Relationships

Base Type

Class Documentation

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.

Public Functions

LanczosFunction1(unsigned int n, double xOffset = 0.0)

Parameters

  • n: order of Lanczos function

  • xOffset: x offset

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

LanczosFunction1(LanczosFunction1 const&)
LanczosFunction1(LanczosFunction1&&)
LanczosFunction1 &operator=(LanczosFunction1 const&)
LanczosFunction1 &operator=(LanczosFunction1&&)
~LanczosFunction1()
std::shared_ptr<Function1<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 concrete subclass must override this method.

Return

a pointer to a deep copy of the function

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

Get the order of the 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

LanczosFunction1()