%% This function computes framewise displacement from an rp file
function [FD,BinMat,PScrub,MOT] = ComputeFD(PathToSubjFolder,SOI,MotThresh,Ses_prefix)

    cd(PathToSubjFolder);
    
    idx = 1;
    
    for s = 1:length(SOI)
        
        cd(SOI{s});
        
        tmp_ses = dir([Ses_prefix,'*']);

        for ses = 1:3
            
            try
                cd(tmp_ses(ses).name);
                
                % Gets the motion information (two motion file names). We want to
                % get the data from the first one
                tmp_mot = cellstr(spm_select('List',pwd,['^' 'rp_f' '.*\.' 'txt' '$']));

                % Mot is a 340 x 6 matrix containing the info the the session
                % considered for all 6 motion parameters
                Mot = textread(tmp_mot{1});
                Mot = Mot(:,1:6);
                
               % Converts last columns into mm
                Mot(:,4:6) = Mot(:,4:6) * 50;

                % Gets the differential
                DMot = diff(Mot,1);
                DMot = [zeros(1,6);DMot];

                % framewise displacement for the considered sessions
                FD{idx} = sum(abs(DMot),2);
                MOT{idx} = Mot;
                    
                cd('..');
                idx = idx + 1;
            catch
                disp('Could not find third session...');
                
                FD{idx} = NaN;
                MOT{idx} = NaN;
                
                idx = idx + 1;
            end
        end 
        
        cd('..');
    end
    
    for i = 1:length(FD)
        if ~isnan(FD{i})
            PScrub(i) = 100*(sum((FD{i} > MotThresh)))/(length(FD{i}));
        else
            PScrub(i) = NaN;
        end
    end
    % Summarizing matrix for frames to scrub 
    BinMat = 0;
    
    cd('..');
end