how can i vectorize it?

HELLO, IT TOOK A LITTLE BEFORE I CODED IT CORRECTLY

I hope I haven't made any mistakes

%%how velocize matrix of array 

%I BUILD DATA IN THIS EXAMPLE
row=10;
col=8;

profit = rand(row,col)

profit = 10×8

0.3436 0.1311 0.9776 0.6418 0.2922 0.8690 0.4831 0.5124 0.9126 0.7900 0.3755 0.3017 0.7737 0.8073 0.8464 0.5552 0.8071 0.9526 0.2701 0.4222 0.4250 0.9831 0.4610 0.1624 0.1542 0.1770 0.9003 0.6316 0.6100 0.8506 0.0065 0.7861 0.5361 0.1805 0.1426 0.6149 0.7982 0.9206 0.3312 0.0705 0.3135 0.0977 0.6855 0.9359 0.2368 0.2731 0.9951 0.7932 0.1589 0.8174 0.4833 0.2497 0.0689 0.0655 0.7721 0.8835 0.9792 0.7773 0.1901 0.0859 0.6659 0.8166 0.6375 0.5151 0.6811 0.0662 0.0089 0.6860 0.7540 0.0032 0.8470 0.7785 0.8207 0.2034 0.2639 0.4568 0.2538 0.2146 0.0026 0.6747

c3 = randi(size(profit,2),row,col);
maxcat = 3;
fr = ones(size(profit));

group=row-1; %group must to be  <row)

c3(rand(group,col)<0.4)=0  % i use this code to turn off some element in c3 

c3 = 10×8

2 3 0 0 6 0 6 8 0 8 7 8 4 6 0 4 7 6 3 8 0 5 0 1 0 7 6 2 6 0 1 3 5 1 0 0 0 4 0 4 5 4 0 3 6 0 2 2 0 5 2 0 0 7 0 8 0 0 4 6 0 5 6 8 3 0 0 0 8 0 3 2 1 7 0 2 0 0 0 6

%%*****************************

%*****************************THIS IS CODE TO VELOCIZE
for r=1:row
      for x=1:group  %(rank group)
         z=c3(x,c3(x,:)>0); %find  element  >0
         A=profit(r,z);
         [~,idxx]=sort(A,'descend');
          idxxx=idxx(maxcat+1:end);
         if ~isempty(idxxx)
             fr(r,z(idxxx))=0;
         end         
      end   
end 

% EDIT: View results
fr

fr = 10×8

0 0 1 1 0 1 0 0 1 0 0 0 0 0 1 0 0 1 0 0 0 1 0 0 0 0 1 0 0 1 0 0 0 0 0 0 1 1 0 0 0 0 1 1 0 0 1 0 0 1 0 0 0 0 1 1 1 0 0 0 0 1 0 0 0 0 0 0 1 0 1 1 1 0 1 0 0 0 0 1

[pipin]

thanks Cris LaPierre

Answer 1

[Bruno Luong]

If you prefer ugly and unreadable code

%I BUILD DATA IN THIS EXAMPLE
row=10;
col=8;

profit = rand(row,col);
c3 = randi(size(profit,2),row,col);
maxcat = 3;
fr = ones(size(profit));

group=row-1; %group must to be  <row)

c3(rand(group,col)<0.4)=0;  % i use this code to turn off some element in c3 
%%*****************************

%*****************************THIS IS CODE TO VELOCIZE
for r=1:row
      for x=1:group  %(rank group)
         z=c3(x,c3(x,:)>0); %find  element  >0
         A=profit(r,z);
         [~,idxx]=sort(A,'descend');
          idxxx=idxx(maxcat+1:end);
         if ~isempty(idxxx)
             fr(r,z(idxxx))=0;
         end         
      end   
end 

% EDIT: View results
fr

fr = 10×8

1 0 1 1 0 0 0 0 1 1 0 0 0 0 0 1 1 1 0 0 0 0 0 1 0 1 0 0 1 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 1 0 0 0 0 0 1 1 0 0 0 0 0 1 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 1 1 0 1 0 0

fr = ones(size(profit));

% vectorize method
[~,j,c] = find(c3(1:group,:)');
c = accumarray(j, c, [], @(i){i});
k = max(cellfun(@height, c)-maxcat, 0);
[~, j] = arrayfun(@(c,k)mink(profit(:,c{1}), k, 2), c, k, 'unif', 0);
cj = cellfun(@(c,j) c(j), c, j, 'unif', 0);
fr((1:row)' + row*([cj{:}]-1)) = 0;

fr

fr = 10×8

1 0 1 1 0 0 0 0 1 1 0 0 0 0 0 1 1 1 0 0 0 0 0 1 0 1 0 0 1 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 1 0 0 0 0 0 1 1 0 0 0 0 0 1 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 1 1 0 1 0 0

[Mike Croucher]

It may be ugly and unreadable but its many times faster! Nice work

I took your code and increased the problem size to give it something more meaty to process: setting

row=1000;
col=8;

give the following times on my machine

origTime =

1.7324

vectorTime =

0.0613

Vectorised method is 28.254690 times faster

Full code for anyone who wants to reproduce this:

%%how velocize matrix of array 
%I BUILD DATA IN THIS EXAMPLE
rng("default")  %For reproducibility
row=1000;
col=8;
profit = rand(row,col);

c3 = randi(size(profit,2),row,col);
maxcat = 3;

group=row-1; %group must to be  <row)
c3(rand(group,col)<0.4)=0;  % i use this code to turn off some element in c3 

%*****************************THIS IS CODE TO VELOCIZE
fr = ones(size(profit));
tic
for r=1:row
      for x=1:group  %(rank group)
         z=c3(x,c3(x,:)>0); %find  element  >0
         A=profit(r,z);
         [~,idxx]=sort(A,'descend');
          idxxx=idxx(maxcat+1:end);
         if ~isempty(idxxx)
             fr(r,z(idxxx))=0;
         end         
      end   
end 
origTime = toc

origTime = 4.2989

fr = ones(size(profit));
% vectorize method
tic
[~,j,c] = find(c3(1:group,:)');
c = accumarray(j, c, [], @(i){i});
k = max(cellfun(@height, c)-maxcat, 0);
[~, j] = arrayfun(@(c,k)mink(profit(:,c{1}), k, 2), c, k, 'unif', 0);
cj = cellfun(@(c,j) c(j), c, j, 'unif', 0);
fr((1:row)' + row*([cj{:}]-1)) = 0;
vectorTime = toc

vectorTime = 0.1545

fprintf("Vectorised method is %f times faster\n",origTime/vectorTime);

Vectorised method is 27.815283 times faster

[pipin]

good work ..thank you