display_structs( t )

function display_structs( t )

%
% function display_structs( t )
%
% This function takes and array of strutures as parameter and after
% searching differences in structures fields prints in a column format all
% the structures marking the differences

% check for correct argument class
if ~isstruct( t(1) )
    disp( ' Error! Argument is not a structure' );
    return;
end

% get filed names
fields   = fieldnames( t(1) );

% get number of fields
n_fields = length( fields );

% find differences in structures fileds
index =  find_struct_diff( t );

% print
for i = 1 : n_fields

    % print field index
    str = sprintf( '[%2d]%20s : ', i, char( fields( i ) ) );
    t_str = [];

    % keep track of struct fields
    s_fields = [];
    
    % format the output string
    for k = 1 : length( t )

        % current field
        c_field = t(k).( char( fields( i ) ) );
%         disp( char( fields( i )  ) )

        % format string for struct fields
        if isstruct( c_field )

            t_str = [str sprintf( '%20s  ', strcat( 'struct [', char( fields( i ) ) ,']' ) ) ];
            disp( t_str );
            s_fields = [s_fields i];
            index = -1;
            break;

        elseif isnumeric( c_field )
            % format string for numeric fields


            disp( str );
            display_struct_array( t, i );
            index = -1;
            break;

            % format string for char fields
        else

            t_str = [t_str sprintf( '%20s  ',c_field ) ];

        end
    end

    % mark differences is present
    if find( index == i )
        disp( strcat( str, t_str, '        <----- different' ) );
    elseif index ~= -1
        disp( strcat( str, t_str ) );
    end
end

function index = find_struct_diff( t )

%
% function index = find_struct_diff( t )
%
% This function takes and array of strutures and compares the same field to
% find differences
%

% return if the array has only one element
if length( t ) == 1
    index = [];
    return
end

s = 1;

% get field names
fields   = fieldnames( t(1) );

% get number of fields
n_fields = length( fields );

% search
for n = 1 : n_fields
    if check_field_diff( t, char( fields( n ) ) )
        index( s ) = n ;
        s = s + 1;
    end
end

return

function b = check_field_diff( t, field_name )

%
% function b = check_field_diff( t, field_name )
%
% Takes an array of structures 't' and check the differences in field
% 'field_name'. It returns 1 if there are some differences while 0 if all
% fields are equal
%

% return value initialization
b = 0;

% structure length
l = length( t );

% check structure length
if l == 1
    return;
end

% compare 'filed_name' in all structures
for k = 1 : l - 1
    for j = k + 1 : l
        if strcmp( t(j - 1).(field_name),  t(j).(field_name) ) ~= 1
            b = 1;
            return;
        end
    end
end

function display_struct_array( t, n )

% get filed names
fields   = fieldnames( t(1) );

% get structure length
l = length( t );

if ~isnumeric( t(1).( char( fields( n ) ) ) )
    return
end

% get array dimension
[ r, c ] = size( t(1).( char( fields( n ) ) ) );

for i = 1 : r
    for j = 1 : c
        
        str = [];
        
        for k = 1 : l
             if k == 1
                 str = sprintf( '                          [%2d-%2d] : %10f', i, j, t(k).( char( fields( n ) ) )(i,j) );
             else
                 str = strcat( str, sprintf('          : %10f', t(k).( char( fields( n ) ) )(i,j) ) );
             end
        end
        
        disp( str );
        
    end
end