MATLAB: Interval between colon-generated vector

Question

Hey all,

I'm getting some weird behavior when I'm creating a vector using the colon function. One would expect if I do a diff function on a vector, it would return a single value, being equal to the second input of colon. I seem to be getting some floating-point instability. Please see the attached screenshot which will better explain the problem. Any suggestions as to what may be happening?

Thanks! Trevor

Answer 1

This is explained in the FAQ, because it is a frequently asked question:

http://www.mathworks.com/matlabcentral/answers/57444-faq-why-is-0-3-0-2-0-1-not-equal-to-zero

So you see, the observed behavior is not "weird", but expected if you consider the limited precision of floating point values according to the IEEE754 standard.