How to find minimum from a group and index at which minimum value is obtained ?

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Dhaval Lodaya
Dhaval Lodaya 2016-7-3
编辑： Dhaval Lodaya 2016-7-4
Hello all,
I have a matrix Engine_data_temp whose 5th column contains values of time (eg: 1;1;1;2;2...600) and 10th column contains values of fuel consumption. I am currently using code shown below to find unique value of time and minimum value of fuel consumed at that time:
(As suggested my one of the community member)
[uniqueT,~,jk]=unique(Engine_data_temp(:,5));
minFc=accumarray(jk,Engine_data_temp(:,10),[],@min);
I also need to find the index at which min values of fuel consumption are being selected at each unique time instances because I need this index to access other columns in matrix Engine_data_temp.
Thank you!
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Dhaval Lodaya
Dhaval Lodaya 2016-7-3
I am looking for a method which does not use for loop for this as it slows down my code. I need to obtain index by vectorization or any other method that is fast.
Thanks in advance!

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Walter Roberson
Walter Roberson 2016-7-3
Create a small function
function r = min_and_idx(x)
[minx, minidx] = min(x);
r = {minx, minidx};
Then you use
minFc = accumarray(jk, Engine_data_temp(:,10), [], @min_and_idx, {});
The result will be a cell array in which some entries might be empty, but if they are not empty then they will be a cell with minimum value and the index of the value relative to the locations that share the same jk value.
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