MATLAB: If statement not executing

faq6.1if statementMATLAB

I'm running into a really weird problem . In my Matlab code, the statement if (time == 0.0992) does not execute, but when I write it in the form if (time== 0.0016*62), it does execute.
Now, since 0.0016*62 is equal to 0.0992, I don't see why the first statement is any different from the second.
NOTE : 'time' is a variable who's value is used as a operating condition for the if statement

Best Answer

Hi, They aren't really equal:
a = 0.0016*62;
b = 0.0992;
isequal(a,b)
This is a well known problem discussed in this forum frequently with the representation of floating-point numbers.
You should use some tolerance statement like
      time = 0.0016*62;
      if(abs(time-0.0992)< eps)
      disp('True');
      else
      disp('False');
      end
Or something similar, trying to insist on equality with floating-point numbers is going to cause you a lot of problems.
Related Question