How to find conditional unique value in matrix

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Berk Gulmez on 3 Feb 2020
Answered: Berk Gulmez on 4 Feb 2020
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,

Spencer Chen on 3 Feb 2020
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

Berk Gulmez on 4 Feb 2020
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]
Thank you so much in advance.

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