Pagewide (single column) footnote in double column document

Question

I am trying to write a long equation in footnote in a double column document (IEEEtran) similar to the attached image. I have tried using "multicols" command but the footnote is starting from the right column and extending out of the page.

I have also tried including the equation in float environment but in that case the figure is placed in the next page and not in the page where I want it be, even though there is enough space.

Please help.

Answer 1

It seems 1-in-2.sty can do the job, which can be used for One-Column Abstract and Footnote in the Two-Column Documents. It has the function:

\mathfootnote{..}

A minimal working example:

\documentclass[twocolumn]{article}
\usepackage{1-in-2}


\title{Title}
%
\author{Author}

\begin{document}

\maketitle

\section{A section}

Blablabla.

An example
\begin{quote}\begin{verbatim}
\mathfootnote{%
 \begin{equation}
 \left\{\begin{array}{c}
  x \\ ...
..........
\end{equation}}
\end{verbatim}\end{quote}
will output an equation in the footnote of this page.

\newcommand{\fat}[1]{\mbox{\boldmath{$#1$}}}
\mathfootnote{
\begin{equation}
\left\{\begin{array}{c} x \\ y \\ z \end{array}\right\}=
\left(\begin{array}{ccc}
 a+b/r                   & c-d/s  & e/f-g \\
                         & h+k/t  & m/n+p \\
 \multicolumn{2}{l}{\mbox{Symm.}} & q-u/v
 \end{array}\right)
\left\{\begin{array}{c} \alpha \\ \beta \\ \gamma \end{array}\right\},
\qquad\mbox{or}\qquad \fat{x}=\fat{C}\,\fat{\lambda}\label{eq:foot}
\end{equation}}

\begin{center} [Eq.(\ref{eq:foot}) is in the footnote.] \end{center}
where $\alpha$ and $\cdots$.


\end{document}

The output:

Answer 2

You can try using a float. I used a similar construction with \twocolumn and it worked fairly well even though it takes more effort to get the float in the right position on the right page then simply using the footnote option. Keep in mind that you need to have float defined in the right place. Try putting it ahead of at least most of your main text.

\usepackage{float}
\newfloat{footnote}{hb}

\begin{document}

text

\begin{footnote*}[hb!]
footnote text
\end{footnote*}

rest of text

\end(document}

It is even simpler if you use multicol instead of the standard twocolumn. Simply end multicols at the end of your main section and put your page wide below that.

\usepackage{float}
\newfloat{footnote}{hb}
\usepackage{multicol}

\begin{document}

\begin{multicols}{2}
text
\end{multicol}

\begin{footnote*}[hb!]
footnote text
\end{footnote*}

\begin(multicols}{2}
rest of text
\end{multicols}

\end(document}