how do I get i to loop through the 55 columns of the excel file one by one. I want i to correspond to the values of the 55 columns to calculate miles driven

filename = 'project3data.xlsx';

num = xlsread('project3data.xlsx');

for i = 1:55

      milesdriven = sum(num(2,2:11))
  end

Answer 1

[Walter Roberson]

Guessing that you only want rows 2 to 11:

        milesdriven(i) = sum(num(2:11, i))

[Khalid Tewfik]

it's not doing what I want the calculation part is right I just need the loop to do the same calculation for each columns from the excel file. The excel file has 55 columns

[Walter Roberson]

Sorry, there is no solution to your question. Your use of

      milesdriven = sum(num(2,2:11))

is incompatible with the possibility that you want to loop over every column, as that code always accesses second row, columns 2 to 11.

Is it possible that you want to loop over 55 rows of the excel, adding columns 2 through 11? That would perhaps be

for i = 1:55
    milesdriven(i) = sum(num(i+1,2:11));
end

The i+1 assumes that for some reason you want to run from row 2 first, row 3 second, and so on to row 56.

Should we assume that row 1 is numeric but for some reason not to be considered?

[Khalid Tewfik]

Yeah you're right I meant rows, but the second bit of code isn't working either

[Walter Roberson]

With no loop:

%adjust these four lines according to your needs
first_row_with_data = 2;
last_row_with_data = size(num, 1);
first_column_with_data = 2;
last_column_with_data = size(num, 2) - 1;

milesdriven = sum( num(first_row_with_data : last_row_with_data, first_column_with_data, last_column_with_data), 2) );

This will sum for each row.

This assumes that your file matches http://www.mathworks.com/matlabcentral/answers/314481-solving-a-for-loop-problem-with-imported-data