# Module profiles¶

Author: Hans Terlouw <gipsy@astro.rug.nl>

## Function¶

profiles.gauest(x, y, rms, cutamp, cutsig, q[, ncomp=200, smode=0, flat=False])
Function to search for gaussian components in a profile.
Parameters: x – a one-dimensional NumPy array (or slice) containing the profile’s x-coordinates. y – a one-dimensional NumPy array (or slice) containing the profile’s values. rms – the r.m.s. noise level of the profile. cutamp – critical amplitude of gaussian. Gaussians below this amplitude will be discarded. cutsig – critical dispersion of gaussian. q – smoothing parameter used in calculating the second derivative of the profile. It must be greater than zero. ncomp – maximum number of gaussian components to be found. It should be $$\geq 1$$. smode – order in which gaussian components are delivered. 0: decreasing amplitude, 1: decreasing dispersion, 2: decreasing flux. flat – True if a ‘flat’ result shoud be returned. See below. a list with up to ncomp tuples of which each tuple contains the amplitude, the centre and the dispersion of the gaussian, in that order. If the argument flat is True, a ‘flat’ list with ncomp * 3 numbers is returned which may directly be used as initial estimates for kmpfit.Fitter.

In this function the second derivative of the profile in the signal region is calculated by fitting a second degree polynomal. The smoothing parameter q determines the number of points used for this ($$2q+1$$). The gaussians are then estimated as described by [Schwarz1968].