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!

What does ceil mean ?

  1. Apr 7, 2006 #1
    Its diifcult to express my question....so, i am posting this

    ceil(4.5) =?
    ceil(4.1)=?
    ceil(4.6)=?
     
  2. jcsd
  3. Apr 7, 2006 #2

    AKG

    User Avatar
    Science Advisor
    Homework Helper

    ceil(x) is the smallest integer which is greater than or equal to x. In particular, if x is an integer, then ceil(x) = x, and if x is not an integer, then ceil(x) > x.
     
  4. Apr 7, 2006 #3
    ceil(4.5)=4 // is it ok ?
    ceil(4.1)=4 //is it ok ?
    ceil(4.6)=5 //is it ok ?
     
  5. Apr 7, 2006 #4

    Integral

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Nope, read the defintion given above, then try again.
     
  6. Apr 7, 2006 #5
    ah...i see, all of them should be 5 .....i had confusion on fractional part .5.
    but i see ..it does not care for .5 which we use for round-off.
     
  7. Apr 7, 2006 #6

    Curious3141

    User Avatar
    Homework Helper

    Yes, all 5.
     
  8. Apr 7, 2006 #7
    thank you for the clarifcation
     
  9. Apr 7, 2006 #8
    Recall that

    [tex]\begin{gathered}
    \forall x \in \left( {a,a + 1} \right)\;{\text{where }}a \in \mathbb{Z}, \hfill \\
    {\text{floor}}\left( x \right) = \left\lfloor x \right\rfloor = a \hfill \\
    {\text{ceil}}\left( x \right) = \left\lceil x \right\rceil = a + 1 \hfill \\
    \end{gathered} [/tex]

    [tex]\forall x \in \mathbb{Z},\;\left\lfloor x \right\rfloor = \left\lceil x \right\rceil = x [/tex]
     
    Last edited: Apr 7, 2006
  10. Apr 7, 2006 #9

    jim mcnamara

    User Avatar

    Staff: Mentor

    ceil -> "goes up" if it needs to, in order reach an integer
    floor -> "goes down" as it needs to, in order to reach an integer
    What happens with negative numbers:

    [tex] floor( -1.1 ) = -2 \; ceil( -1.1 ) = -1 [/tex]
    [tex] floor( -0.1 ) = -1 \; ceil( -0.1 ) = 0 [/tex]
    [tex] floor( 0.9 ) = 0 \; ceil( 0.9 ) = 1[/tex]
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: What does ceil mean ?
  1. What does Ept mean? (Replies: 1)

  2. What does "det" mean? (Replies: 6)

Loading...