specify size output

Hi I (with lots of help) have written the following code:

In = dlmread(FileName);

 [unDates,trash,IDX] = unique(In(:,1:5),'rows');
 Out = [unDates zeros(size(unDates,1),1)];
    for d = 1:size(unDates,1)
    Out(d,end) = mean(In(IDX == d,end));
    end

dlmwrite ('IonOut.csv',Out,'-append','precision','%0.10g','delimiter',',');

end

It does its job of finding unique values column 5 of a csv file that looks like this:

2002,1,1 ,13, 731217, 1119.566899634552 , 8.11440000

however the output file leaves off the last column, I cant see what I have done wrong, can anyone help?

Patrick

Answer 1

[Jan]

Does "Out" contain the wanted values? Or do you want to consider the last two columns of the input? Please check this by "disp(Out)".

INSERTED: Code to consider the 6th column also:

[unDates,trash,IDX] = unique(In(:,1:5), 'rows');
siz = size(unDates);
Out = [unDates, zeros(siz(1), 2)];
for d = 1:siz(1)
  Out(d, 6:7) = mean(In(IDX == d, 6:7), 1);
end

Are you sure, that you want to append the calculated data to the file?

INSERTED: If you do not want to append the values to the file, omit the -append flag.

dlmwrite('IonOut.csv', Out, 'precision','%0.10g', 'delimiter', ',');

[Patrick]

Hi Jan

No Out does not

Not sure I want to append either. the intention is to create a file that gives the average values of column6 and average of column 7 for each date.

Thanks

Patrick

[Oleg Komarov]

use accumarray then

[Patrick]

Hi Oleg,

thanks. have looked into accumarray now and I dont think it wil work as I am looking for a mean of each date, rather than a sum

[Oleg Komarov]

You can specify any function which returns a scalar when applied to a vector:

accumarray(subs,vals,[],@mean)

Answer 2

[Patrick]

Thank you gentlemen,

As you can no doubt see I'm new to MATLAB, Patrick