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: ft_checkdata.m
    path of file: ./repos/malini/Codes/deconvolution - model/spm8/external/fieldtrip/utilities
    
    the code of the file until where you have to start completion: function [data] = ft_checkdata(data, varargin)

% FT_CHECKDATA checks the input data of the main FieldTrip functions, e.g. whether
% the type of data strucure corresponds with the required data. If neccessary
% and possible, this function will adjust the data structure to the input
% requirements (e.g. change dimord, average over trials, convert inside from
% index into logical).
%
% If the input data does NOT correspond to the requirements, t
    
function [data] = fixcsd(data, desired, channelcmb)

% FIXCSD converts univariate frequency domain data (fourierspctrm) into a bivariate
% representation (crsspctrm), or changes the representation of bivariate frequency
% domain data (sparse/full/sparsewithpow, sparsewithpow only works for crsspctrm or
% fourierspctrm)

% Copyright (C) 2010, Jan-Mathijs Schoffelen, Robert Oostenveld

if isfield(data, 'crsspctrm') && isfield(data, 'powspctrm')
  current = 'sparsewithpow';
elseif isfield(data, 'powspctrm')
  current = 'sparsewithpow';
elseif isfield(data, 'fourierspctrm') && ~isfield(data, 'labelcmb')
  current = 'fourier';
elseif ~isfield(data, 'labelcmb')
  current = 'full';
elseif isfield(data, 'labelcmb')
  current = 'sparse';
else
  error('Could not determine the current representation of the %s matrix', param);
end