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: estimate_fwhm1.m
    path of file: ./repos/spm/external/fieldtrip/private
    
    the code of the file until where you have to start completion: function [source] = estimate_fwhm1(source, removecenter)

% ESTIMATE_FWHM1(SOURCE, REMOVECENTER)

    
function [source] = estimate_fwhm1(source, removecenter)

% ESTIMATE_FWHM1(SOURCE, REMOVECENTER)
%
% This function computes the fwhm of the spatial filters, according to
% Barnes et al 2003. the input source-structure should contain the filters
% The fwhm-volume is append