sc_fwhmest.h File Reference

#include <sc_basic.h>

Go to the source code of this file.

Data Structures
struct	_scxydata_
typedef struct _scxydata_	scxydata
cpl_error_code	sc_fwhmest (double *fwhm, double *rms, cpl_table *spec, cpl_table *lines, const cpl_parameterlist *parlist)
int	sc_fwhmest_gaussfunc (int n_data, int n_pars, double *p, double *deviates, double **derivs, void *pdata)

Detailed Description

Header for continuum interpolation and subtraction routine

Author

Marco Barden, Stefan Noll, & ESO In-Kind Team Innsbruck

Date

12 May 2013

Definition in file sc_fwhmest.h.

Typedef Documentation

scxydata

typedef struct _scxydata_ scxydata

Structure for y(x) fitting

Parameters

x	independent variable of model
y	measured "y" values
y_err	measurement uncertainty in y

Function Documentation

sc_fwhmest()

cpl_error_code sc_fwhmest	(	double *	fwhm,
		double *	rms,
		cpl_table *	spec,
		cpl_table *	lines,
		const cpl_parameterlist *	parlist
	)

Estimate FWHM using isolated lines in spectrum.

This routine estimates the FWHM of the lines in a spectrum based on a set of identified isolated lines. Isolated lines are marked in the line list. Firstly, the FWHM is approximated by the value in the line list. Afterwards, fitting the data with a Gaussian is attempted. If the fitting is successful, this value is preferred over the initial estimate.

The input spectrum has to be a CPL table containing (at least) the following columns:

 lambda
 lflux
 class

The column "class" is expected to contain the following values: 0 = Continuum 1 = Line pixel 2 = Line peak 3 = Isolated line peak

Note

In the case of a wavelength-dependent line width (varfwhm = 1), the output FWHM is provided for the central wavelength of the input spectrum.

INPUT:

Parameters

spec	spectrum
lines	line list
parlist	general CPL parameter list

OUTPUT:

Parameters

fwhm	FWHM
rms	RMS error for the FWHM estimate

ERRORS:

• CPL_ERROR_NONE: no error occurred
• SC_ERROR_NDA: no isolated lines in spectra

Definition at line 49 of file sc_fwhmest.c.

References sc_basic_clipmean(), sc_fwhmest_gaussfunc(), and SC_MAXLEN.

Referenced by sc_skycorr_subcont().

sc_fwhmest_gaussfunc()

int sc_fwhmest_gaussfunc	(	int	n_data,
		int	n_pars,
		double *	p,
		double *	deviates,
		double **	derivs,
		void *	pdata
	)

User function for CMPFIT. Provides error-weighted differences between a model Gaussian and a measured line profile.

INPUT:

Parameters

n_data	number of data points
n_pars	number of parameters
p	array of fit parameters
derivs	derivatives (not used)
pdata	private data

OUTPUT:

Parameters

deviates

array of residuals

ERRORS:

• none

Definition at line 265 of file sc_fwhmest.c.

References sc_basic_gaussfunc().

Referenced by sc_fwhmest().