Asked by Lalit Patil
on 27 Nov 2012

Suppose i have a text file that contains 1 column, 68160 rows of random data.

Now, i want

for first 480 rows add 0 in first column,

next 480 rows add 5,

next 480 rows add 10,

next 480 rows add 15,

and continue this with increment of 5, until all columns get finished.. and store all this new data in second column...

I want to write MATLAB code.. So, how to do it...?

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Answer by Muruganandham Subramanian
on 27 Nov 2012

Edited by Muruganandham Subramanian
on 27 Nov 2012

Accepted answer

Check the below code: a=zeros(68160,1);

k=480;

l=5;

j=1;

for i=1:numel(a)

if i<=k

a(i)=a(i)+0;

else

if i <= (j+1)*k

a(i)=a(i)+j*l;

else j=j+1; a(i)=a(i)+j*l; end

end

end

Answer by Jan Simon
on 27 Nov 2012

At first you have to read the file. Therefore you have to know the format of the contents: "random data" could be nearly everything, e.g. floating point numbers like 0.1098435, integers like 134, strings like 'ajdtaoieurgkjahsvbdk', etc. "Adding 0" might imply that you are talking about integer values.

Then a loop seems to be the easiest solution. Just try it and return to the forum in case of problems. It is much easier for the forum users to suggest improvements than to write the complete program from scratch.

Lalit Patil
on 27 Nov 2012

I got it solved...!

clear all;

clc;

fid = fopen('data.txt','wt');

for j=1:500

fprintf(fid,'%f\n',j);

end

fclose(fid);

fileID = fopen('data.txt');

C = textscan(fileID, '%f32');

fclose(fileID);

x=cell2mat(C(:,1));

for m = 0:49

for k = (1+(10*m)):(10+(10*m))

y(k) = x(k) + (0+(5*m));

end

end

y = y';

fid = fopen('data.txt','wt');

for j=1:500

fprintf(fid,'%f %f\n',j,y(j));

end

fclose(fid);

If it is possible to short this code then suggest me...

Opportunities for recent engineering grads.

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