Precision/Rounding in Matlab

Perhaps I should read over the famous article, "What Every Computer Scientist Should Know About Floating-Point Arithmetic."

I'm trying to do a simple comparison of two numbers:

>> isequal(52.8/10, 5.28)

ans =

     0

>> isequal(5.28,5.28)

ans =

     1

Obviously, this is the "wrong" answer. 52.8/10 should be equal to 5.28. It's not.

How do you handle cases like this in matlab? How are you CERTAIN that you are checking for equality correctly?

Thanks.

Answer 1

[the cyclist]

I suggest you look at the Accepted answer to this question, and follow the link in it. http://www.mathworks.com/matlabcentral/answers/69-why-does-1-2-3-1-3-not-equal-zero

[Russell]

Thank you. That answered it nicely.

[the cyclist]

Glad to hear it. You might want to "Accept" the answer, to help future users.