1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Ceiling and floor operators used for min max

  1. Dec 8, 2015 #1
    I remember seeing somewhere people using symbols for ceiling and floor operators together with super/subscripts as substitutes for min and max. Example:
    [tex]\lceil x \rceil ^k[/tex]
    to mean min(x,k).

    Has anyone ever seen this? Where? Thanks!
     
  2. jcsd
  3. Dec 8, 2015 #2
    I'm sorry, I haven't seen this. But I just wanted to say that this certainly ranks among the top 10 worst notations I've ever seen.
     
  4. Dec 8, 2015 #3

    Mark44

    Staff: Mentor

    I haven't seen the notation as you used it, to give the minimum of two numbers, but I have seen this:
    ##\lceil x \rceil##, also called the smallest integer function. It is defined as being the smallest integer that is greater than or equal to x. Many programming languages, including C, C++, and others, have a ceiling function, ceil(x), that does this.
    For example, ##\lceil 1.8 \rceil = 2##.

    The counterpart is the floor function, or greatest integer function, denoted ##\lfloor x \rfloor##. C, C++, and others have floor(x). This is defined as the largest integer that is less than or equal to x.
    For example, ##\lfloor 2.35 \rfloor = 2##.

    I agree with micromass that ##\lceil x \rceil^k## is terrible notation.
     
  5. Dec 8, 2015 #4

    jbriggs444

    User Avatar
    Science Advisor

    It would be a reasonable notation for denoting the smallest multiple of k greater than or equal to x. That is, the generalization of ceiling to a modulus other than 1.
     
  6. Dec 9, 2015 #5
    Yes, that's definitely incorrect notation and most people will confuse it as exponents. As someone else stated, the notation that is correct and seen in programming languages is [7.8]=8 or [5.1]=5. These are more standard and less likely to be confused.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook