How to generate joint frequency table?

Dear experts,

I have two vectors and I want to make a joint frequency table, I tried tabulate but failed, I was wondering what is wrong with my code, and if there is any other code can help me do this?

Many thanks!

Below is the code I tried:

% Two vectors 
Attribute
Assignment_result
% Combine them together 
data=table(Attribute,Assignment_result)
% Tabulate 
joint_freq=tabulate(data.Attribute,data.Assignment_result)
disp(joint_freq)

But matlab suggests 'too many input arguments'

[Jon]

The tabulate function just provides frequencies for one variable, it ony accepts one vector as an argument. This is why you get the error "too many input arguments". Please provide the data that you wish to find the joint frequency of for further guidance.

[Dyuman Joshi]

tabulate() accepts only 1 input, whereas you are giving 2 inputs to it.

What are you trying to do? Calculating the frequency of 1 vector w.r.t to other?

In any case, please attach your data (use the paperclip icon to do so), and mention the output you want to obtain.

[Rouyu Chen]

Thank you Jon and Dyuman Joshi!

Answer 1

[the cyclist]

It isn't perfectly clear what you mean, but I think this does what you intend.

% Set the seed, for reproduciblity
rng default

% Two example vectors
vector1 = randi([1, 3], 5, 1);
vector2 = randi([1, 3], 5, 1);

% Combine the vectors into a matrix
data = [vector1, vector2]

data = 5×2

3 1 3 1 1 2 3 3 2 3

% Unique rows and their indices
[unique_rows, ~, row_indices] = unique(data, 'rows');

% Frequency of each unique row
freq = histcounts(row_indices, 1:size(unique_rows,1)+1);

% Combine the unique rows and their frequencies into a table
freq_table = table(unique_rows, freq', 'VariableNames', {'UniqueRows', 'Frequency'})

freq_table = 4×2 table
    UniqueRows    Frequency
    __________    _________

      1    2          1    
      2    3          1    
      3    1          2    
      3    3          1    

[Rouyu Chen]

Thank you so much!

I was further wondering if it is possible to make the table in the following format?

Thanks again!

[the cyclist]

Ah, you want a cross table:

% Set the seed, for reproduciblity
rng default
% Two example vectors
vector1 = randi([1, 3], 5, 1);
vector2 = randi([1, 3], 5, 1);

[tbl,chi2,p,labels] = crosstab(vector1,vector2)

tbl = 3×3

0 1 0 0 0 1 2 0 1

chi2 = 6.6667

p = 0.1546

labels = 3×2 cell array
    {'1'}    {'1'}
    {'2'}    {'2'}
    {'3'}    {'3'}

[Rouyu Chen]

This is exactly what I am looking for, thank you so much!