Translate code to parallel computing

Hello, everybody

I just would like to ask if somebody could help me to "translate" the follow code to turn it able to run using the parallel computing toolbox:

It is part of one study about lottery, and it is taking too much time to process.

% In this lottery, 15 numbers out of 25 (1 to 25) are drawn. You can win
% specific prizes if you match 11 numbers, or 12 numbers, or 13 numbers,
% or 14 numbers, or 15 numbers.
b = 0; v = 0;
v = 1:25;
combinations = nchoosek(v,15); % matrix with 3268760 lines with all
                               % combinations possible to 15 numbers
                               % chosen between 1 and 25.
lottery = randi(25,2400,15); %simulates 2400 draws for this lottery
number_of_combinations = size(combinations,1); %3268760
number_of_draws = size(lottery,1); %2400
registers = zeros(number_of_combinations,7);
for b = 1:number_of_combinations
    registers(b,1) = b;
end
won15 = 0; won14 = 0; won13 = 0; won12 = 0; won11 = 0;
hit = 0;
i = 0; j1 = 0; j2 = 0; k = 0;
for i = 1:number_of_combinations
    
    for k = 1:number_of_draws
        
        for j1 = 1:15
            
            for j2 = 1:15
                
                if combinations(i,j1) == lottery(k,j2) %check how many times each combinations
                                                       % won some prize considering all 2400 draws
                    hit = hit+1;
                end
                
            end
            
            if hit == 15
                won15 = won15+1;
                registers(i,2) = k; %won the biggest prize in what draw?
                registers(i,3) = won15; %won with 15 numbers how many times?
            end
            
            if hit == 14
                won14 = won14+1;
                registers(i,4) = won14; %won with 14 numbers how many times?
            end
            
            if hit == 13
                won13 = won13+1;
                registers(i,5) = won13; %won with 13 numbers how many times?
            end
            
            if hit == 12
                won12 = won12+1;
                registers(i,6) = won12; %won with 12 numbers how many times?
            end
            
            if hit == 11
                won11 = won11+1;
                registers(i,7) = won11; %won with 11 numbers how many times?
            end
            
        end
        hit = 0;
    end
    
    
    won15 = 0;
    won14 = 0;
    won13 = 0;
    won12 = 0;
    won11 = 0;
    
end

In this code I check how many times each combination possible won considering all 2400 draws.

thanks in advance,

Paulo

Answer 1

[Jan]

% In this lottery, 15 numbers out of 25 (1 to 25) are drawn. You can win
% specific prizes if you match 11 numbers, or 12 numbers, or 13 numbers,
% or 14 numbers, or 15 numbers.

v = 1:25;
comb = nchoosek(uint8(v), 15); % matrix with 3268760 lines with all
% combinations possible to 15 numbers
% chosen between 1 and 25.
lottery = randi(25, 2400, 15, 'uint8'); %simulates 2400 draws for this lottery
nComb = size(comb, 1); %3268760
nDraw = size(lottery, 1); %2400

% registers = zeros(nComb, 7, 'uint32');
% registers(:, 1) = uint32(1):uint32(nComb);

registers = cell(nComb, 1);
registers(:) = {zeros(1, 7, 'uint32')};

parfor i = 1:nComb
   won15 = 0;
   won14 = 0;
   won13 = 0;
   won12 = 0;
   won11 = 0;

   for k = 1:nDraw
      hit = 0;
      for j1 = 1:15
         for j2 = 1:15
            if comb(i,j1) == lottery(k,j2) %check how many times each combinations
               % won some prize considering all 2400 draws
               hit = hit+1;
            end
         end
         
         switch hit
            case 15
               won15 = won15+1;
               registers{i}(2) = k; %won the biggest prize in what draw?
               registers{i}(3) = won15; %won with 15 numbers how many times?
            case 14
               won14 = won14+1;
               registers{i}(4) = won14; %won with 14 numbers how many times?
            case 13
               won13 = won13+1;
               registers{i}(5) = won13; %won with 13 numbers how many times?
            case 12
               won12 = won12+1;
               registers{i}(6) = won12; %won with 12 numbers how many times?
            case 11
               won11 = won11+1;
               registers{i}(7) = won11; %won with 11 numbers how many times?
         end   
      end
   end   
end

registers = cat(1, registers{:});
registers(:, 1) = uint32(1):uint32(nComb)

This procudes the same result, but runs in parallel. But is this really what you want to do?

lottery = randi(25, 2400, 15, 'uint8')

A strange "lottery", which allows repeated numbers. Are you sure?

[Paulo Cunha]

Awesome! Thank you very much!! That was great! About the line, actually I use draws from a real lottery game from my country. I included this line just to turn possible to everybody to test the code.