MATLAB: Sum of Rows

fileioMATLABsum of rows

I have the below sample of txt file:
Stock Date Time Price Volume Stock Category Trade
ETE 04/01/2010 10145959 18.31 500 Big Cap 1
ETE 04/01/2010 10150000 18.01 70 Big Cap 0
ABC 04/01/2010 10190000 18.34 200 Big Cap 1
YYY 04/01/2010 10200000 18.34 100 Big Cap 1
ETE 04/01/2010 10170000 18.54 430 Big Cap 1
How can I calculate the sum of the seventh column (trade) only for rows with value 'ETE' in column one?
Many thanks in advance
Panos

Best Answer

I simply copied and pasted your data into a textfile I named stock_prices.txt, then:
% Retrieve the data...
fid = fopen('stock_prices.txt');
T = textscan(fid,'%s %10s %n %n %n %s %s %n','headerlines',1);
fclose(fid);
% Now that we have the data, do our math...
idx = cellfun(@(x) isequal(x,'ETE'),T{1});
S = sum(T{end}(idx)) % Sum last column, only rows in idx...
S = 
    2
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