lsst.meas.astrom g991b906543+260d7c3927
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Public Member Functions | List of all members
lsst::meas::astrom::sip::LeastSqFitter1d< FittingFunc > Class Template Reference

Fit an lsst::afw::math::Function1 object to a set of data points in one dimension. More...

#include <LeastSqFitter1d.h>

Public Member Functions

 LeastSqFitter1d (const std::vector< double > &x, const std::vector< double > &y, const std::vector< double > &s, int order)
 Fit a 1d polynomial to a set of data points z(x, y)
 
Eigen::VectorXd getParams ()
 Return the best fit parameters as an Eigen::Matrix.
 
Eigen::VectorXd getErrors ()
 Return the 1 sigma uncertainties in the best fit parameters as an Eigen::Matrix.
 
FittingFunc getBestFitFunction ()
 Return the best fit polynomial as a lsst::afw::math::Function1 object.
 
double valueAt (double x)
 Calculate the value of the function at a given point.
 
std::vector< double > residuals ()
 Return a vector of residuals of the fit (i.e the difference between the input y values, and the value of the fitting function at that point.
 
double getChiSq ()
 Return a measure of the goodness of fit.
 
double getReducedChiSq ()
 Return a measure of the goodness of fit.
 

Detailed Description

template<class FittingFunc>
class lsst::meas::astrom::sip::LeastSqFitter1d< FittingFunc >

Fit an lsst::afw::math::Function1 object to a set of data points in one dimension.

The class is templated over the kind of object to fit.

Input is a list of x ordinates for a set of points, the y coordinate, and the uncertainties, s. order is order of the polynomial to fit (e.g if the templated function is lsst::afw::math::PolynomialFunction1, then order=3 => fit a function of the form \(ax^2+bx+c\)

Template Parameters
FittingFuncThe 1d function to fit in both dimensions. Must inherit from lsst::afw::math::Function1
Parameters
xOrdinate of points to fit
yCo-ordinate of pionts to fit
s1 \(\sigma\) uncertainties in z
orderPolynomial order to fit
See also
LeastSqFitter1d

Definition at line 64 of file LeastSqFitter1d.h.

Constructor & Destructor Documentation

◆ LeastSqFitter1d()

template<class FittingFunc >
lsst::meas::astrom::sip::LeastSqFitter1d< FittingFunc >::LeastSqFitter1d ( const std::vector< double > & x,
const std::vector< double > & y,
const std::vector< double > & s,
int order )

Fit a 1d polynomial to a set of data points z(x, y)

Template Parameters
FittingFuncThe type of function to fit. This function extends the base class of lsst::afw::math::Function1
Parameters
xvector of x positions of data
yvector of y positions of data
sVector of measured uncertainties in the values of z
orderOrder of 2d function to fit

Definition at line 104 of file LeastSqFitter1d.h.

Member Function Documentation

◆ getBestFitFunction()

template<class FittingFunc >
FittingFunc lsst::meas::astrom::sip::LeastSqFitter1d< FittingFunc >::getBestFitFunction ( )

Return the best fit polynomial as a lsst::afw::math::Function1 object.

Definition at line 160 of file LeastSqFitter1d.h.

◆ getChiSq()

template<class FittingFunc >
double lsst::meas::astrom::sip::LeastSqFitter1d< FittingFunc >::getChiSq ( )

Return a measure of the goodness of fit.

\[ \chi_r^2 = \sum \left( \frac{y_i - f(x_i)}{s} \right)^2 \]

Definition at line 199 of file LeastSqFitter1d.h.

◆ getErrors()

template<class FittingFunc >
Eigen::VectorXd lsst::meas::astrom::sip::LeastSqFitter1d< FittingFunc >::getErrors ( )

Return the 1 sigma uncertainties in the best fit parameters as an Eigen::Matrix.

Definition at line 149 of file LeastSqFitter1d.h.

◆ getParams()

template<class FittingFunc >
Eigen::VectorXd lsst::meas::astrom::sip::LeastSqFitter1d< FittingFunc >::getParams ( )

Return the best fit parameters as an Eigen::Matrix.

Definition at line 139 of file LeastSqFitter1d.h.

◆ getReducedChiSq()

template<class FittingFunc >
double lsst::meas::astrom::sip::LeastSqFitter1d< FittingFunc >::getReducedChiSq ( )

Return a measure of the goodness of fit.

\[ \chi_r^2 = \sum \left( \frac{y_i - f(x_i)}{s} \right)^2 \div (N-p) \]

Where \( N \) is the number of data points, and \( p \) is the number of parameters in the fit

Definition at line 218 of file LeastSqFitter1d.h.

◆ residuals()

template<class FittingFunc >
std::vector< double > lsst::meas::astrom::sip::LeastSqFitter1d< FittingFunc >::residuals ( )

Return a vector of residuals of the fit (i.e the difference between the input y values, and the value of the fitting function at that point.

Definition at line 182 of file LeastSqFitter1d.h.

◆ valueAt()

template<class FittingFunc >
double lsst::meas::astrom::sip::LeastSqFitter1d< FittingFunc >::valueAt ( double x)

Calculate the value of the function at a given point.

Definition at line 173 of file LeastSqFitter1d.h.


The documentation for this class was generated from the following file: