[Tex/LaTex] IEEEeqnarray page breaks

Question

I am using IEEEeqnarray and have an equation of many lines. LaTeX insists on placing this equation on a new page as there is not enough space remaining at the bottom of the current page for it to fit. I would rather the equation begin on the current page and spill over to the new page in order to avoid a large white space at the bottom of the current page. How may I achieve this?

Thanks…

Answer 1

By default IEEEtran class does allow breaks in equations across pages:

Bottom of page 1

Top of page 2

\documentclass{IEEEtran}

\begin{document}
Text.\newpage\vspace*{22cm}
A multiline display
\begin{IEEEeqnarray}{rCl}
  x &= &y\\
  p &= &q\\
  u &= &v
\end{IEEEeqnarray}

\end{document}

However, loading the amsmath package turns off this behaviour. The amsmath package provides \allowdisplaybreaks which can either be used document wide or applied to a single display as follows:

\documentclass{IEEEtran}

\usepackage{amsmath}

\begin{document}
Text.\newpage\vspace*{22cm}
A multiline display
{\allowdisplaybreaks
\begin{IEEEeqnarray}{rCl}
  x &= &y\\
  p &= &q\\
  u &= &v
\end{IEEEeqnarray}}

\end{document}

Which will give the same equation breaking across pages as before.

Note that IEEEeqnarraybox will never break accross pages.