How do you make parentheses match height when they're split between lines in LaTeX math?

Question

Consider the following example

\begin{equation}
    \begin{split}
        f = & \left( \frac{a}{b} + \right. \\
                   & \left. c \right) + d 
    \end{split}
\end{equation}

In the result, the left parenthesis on the first line is very large, because of the fraction inside. In the second line, since there is no fraction, the parenthesis is small.

How can I make the one on the second line match the one on the first line in height?

I seem to recall something like a "ghost" command, but I cannot find anything on google or in the documentation. — cheshirekow, Jan 02 '10 at 06:36

score 22 · Accepted Answer · edited Feb 07 '19 at 15:39

22

You should use \vphantom, it makes a vertical space equal to its argument and no horizontal space:

\begin{equation}
    \begin{split}
        f = & \left( \frac{a}{b} + \right. \\
                   & \left. \vphantom{\frac{a}{b}} c \right) + d 
    \end{split}
\end{equation}

(I recommend \vphantom over \phantom in this case because \phantom adds horizontal space that you don't need.)

For a lot of great advice on typesetting mathematics, have a look at Math mode by Herbert Voß.

edited Feb 07 '19 at 15:39

DanielTuzes

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answered Jan 03 '10 at 11:53

Alok Singhal

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Yeah, I actually saw that when I found phantom on google. But you're right. Bonus points for the awesome reference. Thanks! – cheshirekow Jan 03 '10 at 12:30
Thanks. I like that document a lot. Anyway, I would have made my post into a comment, but I felt that there was enough independent information to make it a reply. – Alok Singhal Jan 03 '10 at 12:47

score 3 · Answer 2 · answered Jan 02 '10 at 06:40

3

Oh. It's the \phantom{} command

\begin{equation}
    \begin{split}
        f = & \left( \frac{a}{b} + \right. \\
                   & \left. \phantom{\frac{a}{b}} c \right) + d 
    \end{split}
\end{equation}

answered Jan 02 '10 at 06:40

cheshirekow

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score 3 · Answer 3 · answered Sep 02 '10 at 07:22

3

You can also use \big( \big) to set the size specifically.

The order goes (, \big(, \Big(, \bigg(, \Bigg( for increasing bigness.

answered Sep 02 '10 at 07:22

forefinger

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1

yeah, I've used that before, but I don't like having to specify manually... I'm always afraid of having to change the stuff inside and then not notice that the parentheses don't match. – cheshirekow Sep 02 '10 at 17:47

score 0 · Answer 4 · edited Nov 18 '17 at 23:10

0

I think you want to use the \vphantom{} command

\begin{equation}
\begin{split}
    f = & \left( \frac{a}{b} + \right. \\
               & \left. \phantom{\frac{a}{b}} c \right) + d 
\end{split}
\end{equation}

edited Nov 18 '17 at 23:10

Mateusz Piotrowski

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answered Mar 03 '14 at 22:41

KJC2009

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How do you make parentheses match height when they're split between lines in LaTeX math?

4 Answers4