You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: qtParamsGausFit.m
    path of file: ./repos/OSET/matlab/tools/ecg/qt-interval
    
    the code of the file until where you have to start completion: function [GaussParams, varargout] = qtParamsGausFit(ecg, fs, varargin)
% Estimate the Q-T interval and some other Q-T parameters by fitting 
% Gaussian function models.
%
% Syntax:
% GaussParams = qtParamsGausFit(ecg, fs)
% GaussParams = qtParamsGausFit(ecg, fs, rpeaks)
% GaussParams = qtParamsGausFit(ecg, fs, rpeaks, p0)
% GaussParams = qtParamsGausFit(ecg, fs, rpeaks, p0, soi)
% GaussParams = qtParamsGausFit(ecg, fs, rpeaks, p0, soi, lb, ub)
% GaussParams = qtParamsGausFit(ecg, fs, rpeaks, p0, soi, lb, ub, beta)

    
function [GaussParams, varargout] = qtParamsGausFit(ecg, fs, varargin)
% Estimate the Q-T interval and some other Q-T parameters by fitting 
% Gaussian function models.
%
% Syntax:
% GaussParams = qtParamsGausFit(ecg, fs)
% GaussParams = qtParamsGausFit(ecg, fs, rpeaks)
% GaussParams = qtParamsGausFit(ecg, fs, rpeaks, p0)
% GaussParams = qtParamsGausFit(ecg, fs, rpeaks, p0, soi)
% GaussParams = qtParamsGausFit(ecg, fs, rpeaks, p0, soi, lb, ub)
% GaussParams = qtParamsGausFit(ecg, fs, rpeaks, p0, soi, lb, ub, beta)
% GaussParams = qtParamsGausFit(ecg, fs, rpeaks, p0, soi, lb, ub, beta, PrMu, PrCov, varNoise)
% GaussParams = qtParamsGausFit(ecg, fs, rpeaks, p0, soi, lb, ub, beta, PrMu, PrCov, varNoise, options)
% [GaussParams, rPeaks, soi, waveParams, qtInt] = qtParamsGausFit(ecg, fs, ...)
%
% Inputs:
% ecg: Matrix of multichannel ECG data. Each column corresponds to each channel.
% fs: Sampling frequency.
% rpeaks (or hr): If vector, it is an index vector of R peak positions with the
%   same length as the ecg columns. rpeaks has 1 or true values at R peaks and 0
%   or false values elsewhere.
%   If scalar, it is the average heart rate in Hz, used in R peak detection.
% p0: A structure in which p0.q and p0.t are matrices of parameters' initial
%   values. Each column corresponds to each channel, and is like
%   [a1 b1 c1 a2 b2 c2 ...]' where ai, bi, and ci are respectively the i-th
%   Gaussians' amplitudes, widths (sec), and centers (sec). R peak is the reference time
%   for c.
% soi: Segments-of-interest start and end