How to write if condition for a column in a .txt file

I have a variable C that generates the last column of a .txt file. I want to only save the data as a .txt file if the C that is being generated is 1. But it is not working with if condition. However without if condition it prints the complete data perfectly.

If (C==1);
result = [A B C];
fid = fopen('XYZ.txt','wt');
fprintf(fid,'Start\n');
for ii = 1:size(result,1)
 fprintf(fid,'%g\t',result(ii,:));
 fprintf(fid,'\n');
end
fprintf(fid,'End\n');
fclose(fid)
end

[Greg]

Did you use a breakpoint to check the value of C, then step to see if it enters the if block? Occasionally, == fails for integers due to floating point round-off.

[KSSV]

What are the possible values of C ?

Answer 1

[Greg]

I think I understand now - you want to downselect each row based on its value of C. We were looking at C as a scalar (clearly not the case now that I look again, you concatenate C with A and B). Do a search for one of the many questions about non-scalar if conditions - they just don't work.

If you only want to print rows of the matrix where column 3 == 1:

blnKeep = logical(C);
result = result(blnKeep,:);
%%%Your working fprintf code here, without the if condition

Then you should probably update your question to call that out more explicitly.

[Mech Stud]

Thanks. It was helpful.

[Greg]

Happy to help.

Please accept this answer if it is accurate and complete.