Reading full column at a time from a text file

Hi, I am new to Matlab. I have a text file that looks something like this:

1 2 3
4 5 6
7 8 9

I need to add each column separately before I do something with the result. So I need three variables such that

c1 = sum of 1+4+7
c2 = sum of 2+5+8
c3= sum of 3+6+9.

I am reading the text file using using two methods (just trying to see which is better) but they both give me a cell array that reads A = {1, 2, 3, 4, ...}. Here's my code, I appreciate your help.

file_length = 40;
w = [3 -1.5 -2]
entry = [];
fileID = fopen('training_inputs1.txt', 'r');
formatSpec = '%f';
A2 = fscanf(fileID, formatSpec)
A = textscan(fileID, formatSpec);
%r1 = A2(:,1),
for i = A2 %1:file_length
    disp(i(:))

      %value = sprintf(formatspec, i)
      %i2 = i + 1;
      %i3 = i + 3;
      %Y2 = w(2) * i2
      %Y3 = w(3) * i3
  end
  %Y = Y1 + Y2 + Y3
  fclose(fileID);

[Walter Roberson]

You appear to have either one or two lines of headers, with the second header value somehow being involved in reading the file. Could you show the actual format? Can different files have different numbers of columns?

[Faisal Alnahhas]

Which header are you talking about? http://vlm1.uta.edu/~athitsos/courses/cse6363_spring2017/assignments/assignment1/training_inputs1.txt here's what the data looks like exactly. I downloaded the text file in the link

[Walter Roberson]

I missed something in your existing code.

Your A2 = fscanf(fileID, formatSpec) is telling MATLAB to read the entire file as %f format, stopping only when it finds something that cannot be interpreted a floating point number. With your data file, that ends up reading to the end of file. You did not specify a size, so the data will be returned as a column vector.

Then the A = textscan(fileID, formatSpec) tells MATLAB to pick up in the file from where you previously left off and read the rest of the file as floating point numbers, stopping only when it finds something that cannot be interpreted as a floating point number. Because the fscanf already read the entire file, the textscan has nothing to read.

Then your for i = A2 tells MATLAB to iterate with the variable i being set to each column of A2 in turn. A2 only has a single column, so the body of the for loop will be executed once, with i being set to the entire contents of the file...

[Faisal Alnahhas]

Hi again,

The reason I used both fscanf and textscan is because I was trying to see if one of them has advantage over the other. One of them should be commented, it just so happened that it was not when I posted the code. Anyway, what do you recommend I use then?

Answer 1

[Walter Roberson]

We do not recommend that you process one column at a time. Read in all of the columns into a 2D array, and use sum() on that 2D array: the result will be a row vector with one total per column. You do not need different variables for each column: just index the vector.

[Faisal Alnahhas]

Okay. What function do I use to accomplish this goal? And thank you

[Walter Roberson]

data = load('training_inputs1.txt');
sum(data)

[Faisal Alnahhas]

That worked perfectly! Thank you very much. Like I said I'm new to this, today is my 3rd day using Matlab.