Math & Science ⇒ Equation numbers running out of the page

[hajime]

Hello, some of my equations are so long that when latex puts the equation numbers, the numbers are either partially seen or moved to the next line (please refer to the attachments). Any solution to fix these two problems are greatly appreciated. Thanks.

[Stefan Kottwitz]

There's simply not sufficient space at the right.

I recommend to break the wide equation earlier, making several lines. The other options, such as making the margins smaller or reducing the font size of the equations are probably not so good.

Stefan

[hajime]

Thanks for the reply. I tried to reduce the font size already. Nothing changes.
For problem2, is there a way to move the (18) to the right?

[Stefan Kottwitz]

Sure, it depends on how you are producing this equation (which environment?), perhaps show the source code. As also general document settings are important (margins? amsmath?), to verify and to fix it, a minimal working example containing equation and document settings would be useful.

I guess you don't want to see any other equation where the tag (18) is pushed to the right, but your equation with your settings.

Stefan

[hajime]

Thanks Stefan! The source code is:

\begin{eqnarray}
-\frac{A_0}{2}g_z + \sum_{k=-N}^N [-\frac{g_z}{2} - \frac{(\bar z_{0} + z_q)(2 \pi k f_0 )^2}{2} ] (A_k - j B_k) e^{2\pi jkf_0 t} \label{equation18} \nonumber \\
= \frac{a_0}{2} + \frac{1}{2} \sum_{k=-N}^N (a_k - jb_k) e^{2\pi jkf_0 t

\end{eqnarray}

[Stefan Kottwitz]

I see. There are errors:

• There cannot be an empty line within a math environment, because this means a paragraph break for TeX.
• A closing brace is missing in the last expression e^{2\pi jkf_0 t

If I fix this, I get:

equation.png (10.35 KiB) Viewed 11363 times

So the tag is at the right, there's no problem with this code you showed, once the mentioned errors are fixed.

I strongly recommend to avoid eqnarray though, because there are known problems. Use an environment of amsmath instead.

Stefan

[hajime]

Thanks Stefan. I removed \\ and added the closing bracket. Then, the equation looks like the one attached. Also, the two equations below this one got numbered as (18) and (19). Is there anything wrong with my corrections?



\begin{eqnarray}
-\frac{A_0}{2}g_z + \sum_{k=-N}^N [-\frac{g_z}{2} - \frac{(\bar z_{0} + z_q)(2 \pi k f_0 )^2}{2} ] (A_k - j B_k) e^{2\pi jkf_0 t} \label{equation18} \nonumber
= \frac{a_0}{2} + \frac{1}{2} \sum_{k=-N}^N (a_k - jb_k) e^{2\pi jkf_0 t}

\end{eqnarray}

[Stefan Kottwitz]

Yes - I did not say that you should remove the \\. I said remove the empty line.

Stefan

[Stefan Kottwitz]

Here's a complete document, which shows what to use instead of eqnarray: an environment of amsmath, here: multline.

Code: Select all

\documentclass{article}
\usepackage{amsmath}
\begin{document}
\begin{multline}
\label{equation18}
-\frac{A_0}{2}g_z + \sum_{k=-N}^N [-\frac{g_z}{2} - \frac{(\bar z_{0} + z_q)(2 \pi k f_0 )^2}{2} ] (A_k - j B_k) e^{2\pi jkf_0 t} \\
= \frac{a_0}{2} + \frac{1}{2} \sum_{k=-N}^N (a_k - jb_k) e^{2\pi jkf_0 t}
\end{multline}
\end{document}

If you post code, please use the code button, as I did.

Stefan