MathOverflow is a question and answer site for professional mathematicians. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Hey, I need to numerically identify discontinuity points for a function given by a general expression (formula). I am able to evaluate the values at any point. I need it to be fast bu not accurate. The goal is to correctly render functions. With my naive algorithm, I get vertical lines on $x=0$ for $1/x$ and $sign(x)$. The types of discontinuities I need to find are like in the functions $sign(x)$ and $1/x$, that is -,+ adjacent polars and step like functions. I would like to avoid false positives like in the function $sin(1/x)$ which may numerically turn out as discontinues as you approach 0.

Thank You!!!

share|cite|improve this question
I don't think that this is appropriate for this site. You might have more luck at – Loop Space Mar 18 '11 at 8:38
I think this is appropriate for this site. – Paul Tupper Jul 18 '11 at 4:37
up vote 3 down vote accepted

It's going to be hard to find a "fast" way of doing this, but there is an algorithm due to Jeff Tupper for reliably sketching discontinuous functions, which you should be able to adapt to your needs.

share|cite|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.