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: beamformer_sam.m
    path of file: ./repos/malini/Codes/deconvolution - model/spm8/external/fieldtrip/inverse
    
    the code of the file until where you have to start completion: function [dipout] = beamformer_sam(dip, sens, vol, dat, all_cov, varargin)

% BEAMFORMER_SAM scans on pre-defined dipole locations with a single
% dipole and returns the CTF Synthetic Aperture Magnetometry (SAM)
% beamformer estimates. location. Dipole locations that are outside
% the head will return a NaN value.
%
% Use as
%   [dipout] = beamformer_sam(dipin, sens, vol, dat, cov, varargin)
% where
%   dipin       is the input dipole model
%   sens        is the gradiometer definition
%   vol         is the volume conductor definition
%   dat         is the data matrix with the ERP or ERF
%   cov         is the data covariance or cross-spectral density matrix
% and

    
function [dipout] = beamformer_sam(dip, sens, vol, dat, all_cov, varargin)

% BEAMFORMER_SAM scans on pre-defined dipole locations with a single
% dipole and returns the CTF Synthetic Aperture Magnetometry (SAM)
% beamformer estimates. location. Dipole locations that are outside
% the head will return a NaN value.
%
% Use as
%   [dipout] = beamformer_sam(dipin, sens, vol, dat, cov, varargin)
% where
%   dipin       is the input dipole model
%   sens        is the gradiometer definition
%   vol         is the volume conductor definition
%   dat         is the data matrix with the ERP or ERF
%   cov         is the data covariance or cross-spectral density matrix
% and
%   dipout      is the resulting dipole model with all details
%
% The input dipole model consists of
%   dipin.pos   positions for dipole, e.g. regular grid
%   dipin.mom   dipole orientation (optional)
%
% Additional options should be specified in key-value pairs and can be
%   ...
%
% These options influence the forward computation of the leadfield
%   'reducerank'      = reduce the leadfield rank, can be 'no' or a number (e.g. 2)
%   'normalize'       = normalize the leadfield
%   'normalizeparam'  = parameter for depth normalization (default = 0.5)

% Copyright (C) 2009,      Robert Oostenveld
% Copyright (C) 2005-2009, Arjan Hillebrand
% Copyright (C) 2005-2009, Gareth Barnes
%
% $Id: beamformer_sam.m 7123 2012-12-06 21:21:38Z roboos $

if mod(nargin-5,2)
  % the first 5 arguments are fixed, the other arguments should come in pairs
  error('invalid number of optional arguments');
end