Subtract data from two columns and show result in 3rd column

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I have the following data in an excel sheet
A B C
736 373
734 371
725 364
719 361
711 353
706 347
699 342
689 337
680 327
676 318
So basically I want to run this as A(1) - B(1),A(2) - B(2)..A(n) -B(n) and it should create the outputs at C1, C2...Cn respectively. Can anyone help me on this?
  4 Comments
Jasmine
Jasmine on 23 Jul 2014
Edited: Jasmine on 23 Jul 2014
Yes, this is possible. But why wouldn't you just use Excel?
Anyway you need to read the data into MATLAB
data = xlsread('filename')
for i=1:size(data,1)
output(i) = data(i,1)-data(i,2)
end
fulldata = cat(2,data,output)
xlswrite('filename',fulldata)
Or something like that anyway... syntax may be slightly off, as I haven't tested it.
Benjamin
Benjamin on 15 Apr 2019
Edited: Benjamin on 15 Apr 2019
thanks for this helpful answer.
But in every loop, if the size of the matrix (output here) changes Matlab gives error of different matrix sizes. Is there anysolution for that.
FYI: my Matlab code generates a matrix of [A] = n*2 and in every loop (for i = 1:10) n changes. I would like to store all A results in another B matrix.

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Accepted Answer

Joseph Cheng
Joseph Cheng on 23 Jul 2014
Read in the data using xlsread() and write it with xlswrite
A = xlsread(____);
A(:,3) = A(:,1)-A(:,2);
xlswrite(____)
  7 Comments
KRUNAL
KRUNAL on 23 Jul 2014
Did you mean this:
for i=2:11
X = xlsread(dstfile);
X(:,3) = X(:,2)-X(:,1);
Y = int2str (X(:,3));
ind = Y >= 350; %1's where you want to check values again.
Y = cell(size (Y)); %make a cell array so you can have different length text.
Y(ind)= {'check values again'}; %for the indexes (marked with logical 1) put in this text.
Y(~ind)= {'no change'}; %for !ind (inverse) put no change.
xlswrite (dstfile,Y,sheet,'AC');
end
If I write this way, I get output as "no change" in AC, AD and AE column
Joseph Cheng
Joseph Cheng on 23 Jul 2014
Why is there a for loop? does dstfile change base on the loop? Also if it outputs is in AC, AD, and AE what is the size of the Y array? is it one column or 3?

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More Answers (1)

KRUNAL
KRUNAL on 23 Jul 2014
I wrote the code as follows :
for i=2:11
X = xlsread(dstfile);
X(:,3) = X(:,2)-X(:,1);
Y = num2str (X(:,3));
if (Y > 300)
Y = {'ok'};
xlswrite (dstfile,Y,sheet,'AC');
else
Y = {'Check'};
xlswrite (dstfile,Y,sheet,'AC');
end
end
But it is updating only cell AC1 and it is writing "check" in that cell.Can anyone suggest where I am going wrong?
  2 Comments
Joseph Cheng
Joseph Cheng on 23 Jul 2014
because in your if statement you're not going through each Y index. additionally the step above you're going Y = num2str so you're converting it to a string and ask the "STRING" if it is greater than 300.
KRUNAL
KRUNAL on 23 Jul 2014
ok..got my mistake. Finally the code is running..thank you

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