1. Not finding help here? Sign up for a free 30min 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!

How I can use a vertical bar to represent evaluation in LaTeX

  1. Apr 16, 2008 #1
    Hey guys. This might not be the right place for this, but any ideas on how I can use a vertical bar to represent evaluation in LaTeX?

    Example

    [tex] \displaystyle \frac{d}{dt} |_{t=0} f(t) [/tex]

    I would like the vertical bar to be the size of the differential. I've tried using \left|, \right|, \vert, etc. but nothing seems to work. Thanks a lot in advance.
     
    Last edited by a moderator: May 5, 2011
  2. jcsd
  3. Apr 16, 2008 #2

    alphysicist

    User Avatar
    Homework Helper

    Hi Kreizhn,

    Is this it?

    [tex]\left. \frac{d}{dt} \right|_{t=0} f(t)[/tex]

    which is given by

    \left. \frac{d}{dt} \right|_{t=0} f(t)

    Using either \left or \right on a period means the automatic delimiter sizing takes place, but only one delimiter is shown.
     
  4. Apr 16, 2008 #3
    Excellent, thank you
     
  5. Apr 16, 2008 #4

    robphy

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    \frac{d}{dt} \bigg|_{t=0} f(t) achieves a similar effect
    with manual sizing (by using two g's) and the unneeded \left. tag.

    [tex]\frac{d}{dt} \bigg|_{t=0} f(t)[/tex]
     
  6. May 5, 2011 #5
    Re: LaTeX

    I'm using lyx and I'm having difficulty trying to find the code for this vertical line. Any suggestions? I use the | but it's extremely small.
     
  7. May 5, 2011 #6
    Re: LaTeX

    Maybe try \|?

    The height of the vertical line will be determined by the {stuff} in between the \left. {stuff} \right|. If it's not naturally big, you may want to add an "invisible tower." My invisible tower is called \xstrut, and is defined as follows

    \newlength{\myVSpace}% the height of the box
    \setlength{\myVSpace}{3ex}% the default,
    \newcommand\xstrut{\raisebox{-.5\myVSpace}% symmetric behaviour,
    {\rule{0pt}{\myVSpace}}%
    }
    To change the height of the box, change

    \setlength{\myVSpace}{Your number here}
     
  8. Feb 19, 2012 #7
    \mathbf{M \bigg|_{x^k} \Delta x^k = -f(x^k)}
    [tex]
    \mathbf{M \bigg|_{x^k} \Delta x^k = -f(x^k)}[/tex]
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: How I can use a vertical bar to represent evaluation in LaTeX
  1. LaTeX, how can i? (Replies: 6)

  2. How to use Latex (Replies: 8)

Loading...