finding probability in Matlab

Hello,

I was given this question (1)

I did sovle it and here is the answer:

then I had to write a basic MATLAB code as given in Q2

here is my start

clc;clear all; close all;

Genes1 = randi(500,1,21) %% generate 20 out of 500 genes

Genes2 = randi(500,1,21) %% secon trail of generating

C = intersect(Genes1,Genes2) %% find the common genes

N = numel(C) %% number of common genes

my question is how to find the probablity in matlab given the code above(or different one)?

Answer 1

[Alan Stevens]

You could use a Monte-Carlo simulation approach. Building on your calculations we have, for example:

% Monte_Carlo calculation of probability
N = 10^4;   % Number of trials
C = 0;      % Initialise count
for i = 1:N
    Genes1 = randi(500,1,20); %% generate 20 out of 500 genes
    Genes2 = randi(500,1,20); %% secon trail of generating
    CommonGenes = intersect(Genes1,Genes2); %% find the common genes
    
    if ~isempty(CommonGenes)
        C = C + 1;
    end
end

p = C/N; % Probability
disp(p)

On second thoughts, randi can geerate repeated numbers. For non-repeated sets, replace

    Genes1 = randi(500,1,20); %% generate 20 out of 500 genes
    Genes2 = randi(500,1,20); %% secon trail of generating

by

    Genes1 = randperm(500,20); %% generate 20 out of 500 genes
    Genes2 = randperm(500,20); %% secon trail of generating

[Khadija Sulail]

thank you that helped !