casa  5.7.0-16
casacore::LatticeFit Class Reference

Fit every line of pixels parallel to any axis in a Lattice. More...

`#include <LatticeFit.h>`

## Static Public Member Functions

static uInt fitProfiles (Lattice< Float > &outImage, Vector< Float > &fittedParameters, LinearFit< Float > &fitter, const Lattice< Float > &inImage, uInt whichAxis, const Vector< Bool > &fitMask, Bool returnResiduals)
Fit baseline to lattice. More...

static uInt fitProfiles (MaskedLattice< Float > *pOutFit, MaskedLattice< Float > *pOutResid, MaskedLattice< Float > &in, Lattice< Float > *pSigma, LinearFit< Float > &fitter, uInt axis, Bool showProgress=False)
Fit baseline to MaskedLattice. More...

## Detailed Description

Fit every line of pixels parallel to any axis in a Lattice.

### Synopsis

For every line in the lattice parallel to axis number `whichAxis` (often axis number 2, typically the frequency axis in a spectral line cube) independently fit the functions in fitter at the positions where `fitMask` is true.

### Example

Suppose one wanted to subtract a linear polynomial from every spectrum (3d axis) in an image. One could do this as follows:

Image<Float> myImage("myimage"); // Get the image
uInt nchan = myImage.shape()(2); // 0 relative axis number
// Set up the fitter
Polynomial<AutoDiff<Float> > linear(1);
LinearFitSVD<Float> fitter;
fitter.setFunction(linear);
Vector<Float> fittedParameters,
// Set up a mask indicating what channels we want to fit over. We want
// to fit over all channels.
// Do the fit. True means subtract the fit from the model. In this case,
// We overwrite the input with the output.
fitProfiles (myImage, fittedParameters,fitter, myImage, 2, fitMask, True);

### Motivation

Baseline fitting/continuum subtraction are important functions. This function essentially implements the IMLIN algorithm.

### To Do

• Save the model parameters in an (optional) other lattice.
• Use logging classes, rather than the raw GlishSysEventSource.
• Allow per-pixel weights.
• Allow non-linear as well as linear LSQ fits.

Definition at line 96 of file LatticeFit.h.

## Member Function Documentation

 static uInt casacore::LatticeFit::fitProfiles ( Lattice< Float > & outImage, Vector< Float > & fittedParameters, LinearFit< Float > & fitter, const Lattice< Float > & inImage, uInt whichAxis, const Vector< Bool > & fitMask, Bool returnResiduals )
static

Fit baseline to lattice.

Presently the fit parameters, other than the last one(s) in fitter, are lost. If `returnResiduals` is True, return data-fit, otherwise return the fit. For baseline and continuum subtraction, returnResiduals would normally be True.

 static uInt casacore::LatticeFit::fitProfiles ( MaskedLattice< Float > * pOutFit, MaskedLattice< Float > * pOutResid, MaskedLattice< Float > & in, Lattice< Float > * pSigma, LinearFit< Float > & fitter, uInt axis, Bool showProgress = `False` )
static

Fit baseline to MaskedLattice.

Fit and residuals can be optionally written (leave pointers at zero to not write out these lattices) You can optionally specify a weights lattice (1.0 if not given).

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