How to find conditional unique value in matrix

Helle everyone,

I have a dataset;

x = [100 10 1; 100 30 2 ; 100 40 1; 100 75 1 ; 101 10 2; 101 25 2 ; 101 50 1 ; 102 20 1; 102 25 2; 103 50 1]

the first column indicates order number,

the second column indicates cost,

the third column indicates firm. There are 2 firms and I want to find maximum value of order cost with respect to firms. If there is cost for that firm, I want to fill value as 0.

So, I want to find 2 different matrices.

for the firm 1;

firm1 = [100 75 1;101 50 1; 102 20 1; 103 50 1]

and firm2

firm2 = [100 30 2; 101 50 2; 102 20 2; 103 0 2]

note that for order number 103 cost value is 0 because there is no information for firm 2 about this order.

I want to use unique command with a loop but it fails.

Thank you so much in advance.

Regards,

Answer 1

[Spencer Chen]

Maybe this will get you started:

ux1 = unique(x(:,1));   % Find your unique order numbers
for xx = 1:numel(ux1)
    idx = x(:,1) == ux1(xx) & x(:,3) == 1;  % Find all orders from firm 1 with the desired order number
    ...
end

Blessings,

Spencer

Answer 2

[Berk Gulmez]

Thanks for comment,

with using unique command, I found required values.

x = [100 10 1; 100 30 2 ; 100 40 1; 100 75 1 ; 101 10 2; 101 25 2 ; 101 50 1 ; 102 20 1; 102 25 2; 103 50 1];

%finding indices of first firm

xr = find(x(:,3)==1);

%subset of first firm

xrr = x(xr,:);

%finding indices of second firm

xl = find(x(:,3)==2);

%subset of second firm

xll = x(xl,:);

%finding the biggest cost value with respect to order for the first firm

[~,I]=unique(xrr(:,1),'last');

xRMD = xrr(I,:);

%finding the biggest cost value with respect to order for the first firm

[~,I]=unique(xll(:,1),'last');

xLMD = xll(I,:);

%finding order number

ux1=unique(x(:,1));

now I need to find a result like that but ı cannot use ismember function correctly,

result = [100 75 30; 101 50 25; 102 20 25; 103 50 0]

can you please give an advice?

Thank you so much in advance.