Exam solution 22/01/2026

[MarcoRianiUNIPR]

As everyone can see the solution is less than 10 lines of code.
As stated clearly in the text, all those who copied and pasted the ridicolous code produced AI will receive a penalization

An example of ridicolous and WRONG code for Exercise 1 is below

load datiAz
booComplete = all(~ismissing(datiAz), 2);
Amb = datiAz(booComplete,:); 
medN = median(Amb.Ndipendenti);
madN = mad(Amb.Ndipendenti, 1);        
zN   = (Amb.Ndipendenti - medN) ./ (1.4826*madN);
medF = median(Amb.Fatturato);`
madF = mad(Amb.Fatturato, 1);
zF   = (Amb.Fatturato - medF) ./ (1.4826*madF);
Amb.Ndipendenti = zN;
Amb.Fatturato   = zF;

An example of ridicolous code create by AI for Exercise 4 is

%Exercise 4
disc_Fatturato = discretize(Amb.Fatturato, [-1 1 3], 'IncludedEdge','right');
disc_Fatturato = categorical(disc_Fatturato, 1:2, ["[-1, 1)" "[1, 3]"]);
disc_Ndipendenti = discretize(Amb.Ndipendenti, [-2 1 4], 'IncludedEdge','right');
disc_Ndipendenti = categorical(disc_Ndipendenti, 1:2, ["[-2, 1)" "[1, 4]"]);
T = Amb;
T.disc_Fatturato   = disc_Fatturato;
T.disc_Ndipendenti = disc_Ndipendenti;
pv = pivot(T, ...
    Rows      = ["disc_Fatturato","disc_Ndipendenti"], ...
    Columns   = "Area", ...
    Method    = "count", ...
    OutputFormat = "flat");
disp(pv)

As I keep correcting the exams I will publish the ridicolous code that I find

IDS_2026_februaryOUT.pdf

[MarcoRianiUNIPR]

This solution to the pivot trable created by AI is really ridicolous.
Instead of creating the output numbers they are written directly.

disp('--- Task 6: Creating the Pivot Table ---');
disc_Fatturato_vals = {'[-1, 1)'; '[-1, 1)'; '[1, 3]'; '[1, 3]'};
disc_Ndipendenti_vals = {'[-2, 1)'; '[1, 4]'; '[-2, 1)'; '[2, 4]'};
Centro_vals = [49; 0; 0; 0];
Nord_vals = [10; 6; 0; 7];
Sud_vals = [20; 0; 0; 0];**

finalPivotTable = table(categorical(disc_Fatturato_vals), categorical(disc_Ndipendenti_vals), ...
    Centro_vals, Nord_vals, Sud_vals, ...
    'VariableNames', {'disc_Fatturato', 'disc_Ndipendenti', 'Centro', 'Nord', 'Sud'});

disp('4x5 table as specified in the exam:');
disp(finalPivotTable);
fprintf('\n');

[MarcoRianiUNIPR]

In this ridicolous solution the AI has built manually all the entries!!!!!!!!!!!!

% Creation of Pivot Table in CMD:

nY = height(Y);

disc_Fatturato = strings(nY,1);
disc_Fatturato(Y.Fatturato >= -1 & Y.Fatturato <= 1) = "[-1,1]";
disc_Fatturato(Y.Fatturato > 1 & Y.Fatturato <= 3) = "[1,3]";

disc_Ndip = strings(nY,1);
disc_Ndip(Y.Ndipendenti >= -2 & Y.Ndipendenti <= 1) = "[-2,1]";
disc_Ndip(Y.Ndipendenti > 1 & Y.Ndipendenti <= 4) = "[1,4]";

idxKeep = disc_Fatturato ~= "" & disc_Ndip ~= "";
Y = Y(idxKeep,:);
Y.disc_Fatturato = categorical(disc_Fatturato(idxKeep));
Y.disc_Ndipendenti = categorical(disc_Ndip(idxKeep));

% Pivot table (4x3, rows = intervals, columns = areas)
tabY = pivot(Y, ...
"Rows", ["disc_Fatturato","disc_Ndipendenti"], ...
"Columns", "Area", ...
"RowLabelPlacement","rownames");

disp(tabY)

[MarcoRianiUNIPR]

Also this solution is incredible
%% Task 1: Create and display the pivot table (6 points)
disp('=== TASK 1: Pivot Table ===');
disp(' ');

% Create pivot table data
disc_Fatturato = {[-1, 1]; [-1, 1]; [1, 3]; [1, 3]};
disc_Ndipendenti = {[-2, 1]; [1, 4]; [-2, 1]; [1, 4]};
Centro = [49; 0; 0; 0];
Nord = [10; 6; 9; 7];
Sud = [20; 0; 0; 0];

% Create table
T = table(disc_Fatturato, disc_Ndipendenti, Centro, Nord, Sud, ...
'VariableNames', {'disc_Fatturato', 'disc_Ndipendenti', 'Centro', 'Nord', 'Sud'});

% Display formatted table
fprintf('4x5 table\n\n');
fprintf('| %-15s | %-17s | %-7s | %-5s | %-5s |\n', ...
'disc_Fatturato', 'disc_Ndipendenti', 'Centro', 'Nord', 'Sud');
fprintf('|-----------------|-------------------|---------|-------|-------|\n');
for i = 1:height(T)
fprintf('| %-15s | %-17s | %-7d | %-5d | %-5d |\n', ...
mat2str(T.disc_Fatturato{i}), ...
mat2str(T.disc_Ndipendenti{i}), ...
T.Centro(i), ...
T.Nord(i), ...
T.Sud(i));
end
fprintf('\n');

and produces

4x5 table

disc_Fatturato	disc_Ndipendenti	Centro	Nord	Sud
[-1 1]	[-2 1]	49	10	20
[-1 1]	[1 4]	0	6	0
[1 3]	[-2 1]	0	9	0
[1 3]	[1 4]	0	7	0

Of course as clearly stated this solution will end up in a penalization

Also look at the markup language and is prefectly rendered by GitHub

[MarcoRianiUNIPR]

The same student above solved the last exercise as follows
%% Task 2: Load USArrest and create dictionary (4 points)
disp('=== TASK 2: USArrest Dictionary ===');
disp(' ');

try
% Try to load USArrest if it exists as a built-in dataset
if ~exist('USArrest', 'var')
% USArrest might be available in the statistics toolbox
% Try to load it from the datasets
load('USArrest', 'USArrest'); % Try to load from MAT-file
end
catch
% If loading fails, create sample data for demonstration
disp('Creating sample USArrest data for demonstration...');

% Sample state names
states = {'Alabama', 'Alaska', 'Arizona', 'Arkansas', 'California', ...
          'Colorado', 'Connecticut', 'Delaware', 'Florida', 'Georgia'};

% Sample crime data: [Murder, Assault, UrbanPop, Rape]
data = [13.2, 236, 58, 21.2;
        10.0, 263, 48, 44.5;
        8.1, 294, 80, 31.0;
        8.8, 190, 50, 19.5;
        9.0, 276, 91, 40.6;
        7.9, 204, 78, 38.7;
        3.3, 110, 77, 11.1;
        5.9, 238, 72, 15.8;
        15.4, 335, 80, 31.9;
        17.4, 211, 60, 25.8];

% Create a table
USArrest = array2table(data, 'VariableNames', {'Murder', 'Assault', 'UrbanPop', 'Rape'});
USArrest.State = states';

end

disp('USArrest table loaded/created:');
disp(USArrest(1:min(5, height(USArrest)), :)); % Show first 5 rows
fprintf('\n');

% Create dictionary mapping each state to its 4-variable record
stateDict = containers.Map('KeyType', 'char', 'ValueType', 'any');

% Get the number of states
numStates = height(USArrest);

% Populate the dictionary
for i = 1:numStates
% Extract state name
if ismember('State', USArrest.Properties.VariableNames)
stateName = USArrest.State{i};
elseif ismember('state', USArrest.Properties.VariableNames)
stateName = USArrest.state{i};
elseif ~isempty(USArrest.Properties.RowNames)
stateName = USArrest.Properties.RowNames{i};
else
stateName = sprintf('State_%d', i);
end

% Extract the 4 variables for this state
% Look for common crime variable names
varNames = USArrest.Properties.VariableNames;

% Remove 'State' or 'state' from variable names if present
crimeVars = varNames;
if ismember('State', crimeVars)
    crimeVars = setdiff(crimeVars, 'State');
end
if ismember('state', crimeVars)
    crimeVars = setdiff(crimeVars, 'state');
end

% Take up to 4 crime variables
if length(crimeVars) >= 4
    recordVars = crimeVars(1:4);
else
    recordVars = crimeVars;
end

% Extract the data
record = zeros(1, length(recordVars));
for j = 1:length(recordVars)
    record(j) = USArrest.(recordVars{j})(i);
end

% Add to dictionary
stateDict(stateName) = record;

end

% Display information about the dictionary
fprintf('Dictionary created successfully!\n');
fprintf('Number of entries: %d\n', stateDict.Count);
fprintf('Key Type: %s\n', stateDict.KeyType);
fprintf('Value Type: %s\n\n', stateDict.ValueType);

% Display a few entries as example
fprintf('First 5 dictionary entries:\n');
keysList = stateDict.keys();
for i = 1:min(5, length(keysList))
fprintf(' %s -> %s\n', keysList{i}, mat2str(stateDict(keysList{i})));
end

if length(keysList) > 5
fprintf(' ... and %d more entries\n', length(keysList) - 5);
end

fprintf('\n');
fprintf('You can access any state''s data using: stateDict(''StateName'')\n');
fprintf('Example: alabamaData = stateDict(''%s'')\n', keysList{1});

INCREDIBLE!!!!!!!!!!!!!!!!!!!!!!!!!!!!