[Tex/LaTex] How to put a long equation spanning two columns while using IEEEtran

amsmathcolumnbreakequations

I am using the IEEEtran document class to generate my PDF file so that it has two columns, but now I get a long equation and I cannot put it into just one of the two columns. Thus I used \onecolumn at the beginning of my equation and \twocolumn at the end of my equation like this:

\documentclass[journal]{IEEEtran}
\begin{document}
...
\onecolumn
\begin{align}
    T\triangleq{} &
    \int_{0}^{\infty}
    \frac
    {\gamma^{k+m_2-1}\exp\Bigl(-\frac{m_2\gamma}{\bar\gamma_2}\Bigr)}
    {1+\Bigl(\frac{(m_1+s\bar\gamma_1)\gamma}{cm_1}\Bigr)^{m_1}(1+\frac{1}{c}\gamma_2)
        ^{\lceil m_1 \rceil -m_1}}
    \,\mathrm{d}\gamma
    \\
    \nonumber
    ={}& C\int_{0}^{\infty}\gamma^{k+m_2-1}\exp\Biggl(-\frac{m_2\gamma}{\bar\gamma_2}\Biggr)
    \\
    &\times H_{1,1}^{1,1}
    \left[
    \frac{(m_1+s\bar\gamma_1)\gamma}{cm_1}
    \;\middle|\;
    \begin{gathered} (1-m_1,1) \\ (0,1)\end{gathered}
    \right]
    H_{1,1}^{1,1}
    \left[
    \frac{\gamma}{c}
    \;\middle|\;
    t \begin{gathered} (1-\lceil m_1 \rceil +m_1,1) \\ (0,1)\end{gathered}
    \right]
    \mathrm{d}\gamma
    \\
    ={}& C\Biggl(\frac{\bar\gamma_2}{m_2}\Biggr)^{k+m_2}
    H_{1,\,[1:\,1],\,0,\,[1:\,1]}^{1,\,1,\,1,\,1,\,1}
    \left[
    \begin{gathered}
        \frac{(m_1+s\bar{\gamma}^{}_{1})\bar{\gamma}^{}_{2}}{c\,m_1m_2} \\
        \frac{\bar{\gamma}^{}_{2}}{c\,m_2}
    \end{gathered}
    \;\middle|\;
    \begin{gathered}
        (k+m_2,1) \\
        (1-m_1,1);(1-\lceil{m_1}\rceil+m_1,) \\
        - \\
        (0,1);(0,1)
    \end{gathered}
    \right]
    \\
    ={}& C\Biggl(\frac{\bar\gamma_2}{m_2}\Biggr)^{k+m_2}
    G_{1,\,[1:\,1],\,0,\,[1:\,1]}^{1,\,1,\,1,\,1,\,1}
    \left[
    \begin{gathered}
        \frac{(m_1+s\bar{\gamma}^{}_{1})\bar{\gamma}^{}_{2}}{c\,m_1m_2}\\
        \frac{\bar{\gamma}_{_2}}{c\,m_2}
    \end{gathered}
    \;\middle|\;
    \begin{gathered}
        k+m_2\\1-m_1;1-\lceil{m_1}\rceil+m_1 \\
        - \\
        0;0\end{gathered}
    \right].
\end{align}
\twocolumn

which will generate an equation in the middle of the paper like this:
The long equation I want to break
But I was told that the format is not suitable for publication, and I have to put this long equation spanning two columns. What's the solution?

Best Answer

We can make the whole group fit one column if we break some equations and use the \medmath command (from nccmath) which reduces the formulae size by ~20%.

I add another solution based on the strip environment from cuted (a component of the sttools bundle) which allows to have full width formulae in a two-column environment, but in contrast to table*, is inserted at the point where it is called.

\documentclass[journal]{IEEEtran}
\usepackage{mathtools,amssymb,lipsum, nccmath}
\DeclarePairedDelimiter{\ceil}{\lceil}{\rceil}
\usepackage{cuted}
\setlength\stripsep{3pt plus 1pt minus 1pt}

\begin{document}

\lipsum[1-2] % filler text

\begin{align}
  & T
  \triangleq
  \int_{0}^{\infty}
  \frac
  {\gamma^{k+m_2-1}\exp\Bigl(-\mfrac{m_2\gamma}{\bar\gamma_2}\Bigr)}
  {1+\Bigl(\mfrac{(m_1+s\bar\gamma_1)\gamma}{cm_1}\Bigr)^{\mathstrut m_1}
  \Bigl(1+\mfrac{1}{c}\gamma_2\Bigr)^{\ceil{m_1}-m_1}}
  \,\mathrm{d}\gamma
  \\[1ex]
    & =\!\begin{aligned}[t]\medmath{C\!\int_{0}^{\infty}\!\!\gamma^{k+m_2-1}} & \medmath{\exp\Bigl(\!-\frac{m_2\gamma}{\bar\gamma_2}\!\Bigr)
  H_{1,1}^{1,1}
  \mathrlap{\left[
  \frac{(m_1\!+s\bar\gamma_1)\gamma}{cm_1}
  \middle\vert
  \begin{gathered} (1\!- m_1,1) \\ (0,1)\end{gathered}
  \right]}}\\
  & {}\times\medmath{H_{1,1}^{1,1}
  \left[
  \frac{\gamma}{c}
  \;\middle|\;
  t \begin{gathered} (1-\ceil{m_1} +m_1,1) \\ (0,1)\end{gathered}
  \right]
  \mathrm{d}\gamma}
  \end{aligned}
  \\
  & =\!\begin{aligned}[t] \medmath{
  C\biggl(\frac{\bar\gamma_2}{m_2}\biggr)^{k+m_2}} & \medmath{H_{1,\,[1:1],\,0,\,[1:1]} ^{1,\,1,\,1,\,1,\,1}}\times {}\\[-1ex]
  \MoveEqLeft\medmath{\times\left[
  \begin{gathered}
  \frac{(m_1\!+s\bar{\gamma}^{}_{1})\bar{\gamma}^{}_{2}}{c\,m_1m_2} \\
  \frac{\bar{\gamma}^{}_{2}}{c\,m_2}
  \end{gathered}
  \middle\vert
  \begin{gathered}
  (k+m_2,1) \\
  (1\!- m_1,1);(1\!-\!\ceil{m_1}\!+ m_1,) \\
  - \\
  (0,1);(0,1)
  \end{gathered}
  \right]}
  \end{aligned}
  \\[1ex]
  & =\!\begin{aligned}[t] \medmath{C\biggl(\frac{\bar\gamma_2}{m_2}\biggr)^{k+m_2}}
  & \medmath{G_{1,\,[1:1],\,0,\,[1:1]}^{1,\,1,\,1,\,1,\,1}}\times{}\\[-1ex]
  \MoveEqLeft\times \medmath{\left[
  \begin{gathered}
  \frac{(m_1+s\bar{\gamma}^{}_{1})\bar{\gamma}^{}_{2}}{c\,m_1m_2}\\
  \frac{\bar{\gamma}_{_2}}{c\,m_2}
  \end{gathered}
  \;\middle|\;
  \begin{gathered}
  k+m_2\\
  1-m_1;1-\ceil{m_1}+m_1 \\
  - \\
  0;0
  \end{gathered}
  \right]}.
  \end{aligned}
\end{align}

\lipsum[3-6] % more filler text
\end{document}

enter image description here

\documentclass[journal]{IEEEtran}
\usepackage{mathtools,amssymb,lipsum}
\DeclarePairedDelimiter{\ceil}{\lceil}{\rceil}
\usepackage{cuted}
\setlength\stripsep{3pt plus 1pt minus 1pt}

\begin{document}

\lipsum[1-2] % filler text

\begin{strip}
  \begin{align}
    T & \triangleq
    \int_{0}^{\infty}
    \frac
    {\gamma^{k+m_2-1}\exp\Bigl(-\frac{m_2\gamma}{\bar\gamma_2}\Bigr)}
    {1+\Bigl(\frac{(m_1+s\bar\gamma_1)\gamma}{cm_1}\Bigr)^{\mathstrut m_1}
    \bigl(1+\frac{1}{c}\gamma_2\bigr)^{\ceil{m_1}-m_1}}
    \,\mathrm{d}\gamma
    \\
      & = C\int_{0}^{\infty}\gamma^{k+m_2-1}\exp\Bigl(-\frac{m_2\gamma}{\bar\gamma_2}\Bigr)
    H_{1,1}^{1,1}
    \left[
    \frac{(m_1+s\bar\gamma_1)\gamma}{cm_1}
    \;\middle|\;
    \begin{gathered} (1-m_1,1) \\ (0,1)\end{gathered}
    \right]
    H_{1,1}^{1,1}
    \left[
    \frac{\gamma}{c}
    \;\middle|\;
    t \begin{gathered} (1-\ceil{m_1} +m_1,1) \\ (0,1)\end{gathered}
    \right]
    \mathrm{d}\gamma
    \\
      & = C\biggl(\frac{\bar\gamma_2}{m_2}\biggr)^{k+m_2}
    H_{1,\,[1:\,1],\,0,\,[1:\,1]}^{1,\,1,\,1,\,1,\,1}
    \left[
    \begin{gathered}
    \frac{(m_1+s\bar{\gamma}^{}_{1})\bar{\gamma}^{}_{2}}{c\,m_1m_2} \\
    \frac{\bar{\gamma}^{}_{2}}{c\,m_2}
    \end{gathered}
    \;\middle|\;
    \begin{gathered}
    (k+m_2,1) \\
    (1-m_1,1);(1-\ceil{m_1}+m_1,) \\
    - \\
    (0,1);(0,1)
    \end{gathered}
    \right]
    \\
      & = C\biggl(\frac{\bar\gamma_2}{m_2}\biggr)^{k+m_2}
    G_{1,\,[1:\,1],\,0,\,[1:\,1]}^{1,\,1,\,1,\,1,\,1}
    \left[
    \begin{gathered}
    \frac{(m_1+s\bar{\gamma}^{}_{1})\bar{\gamma}^{}_{2}}{c\,m_1m_2}\\
    \frac{\bar{\gamma}_{_2}}{c\,m_2}
    \end{gathered}
    \;\middle|\;
    \begin{gathered}
    k+m_2\\
    1-m_1;1-\ceil{m_1}+m_1 \\
    - \\
    0;0
    \end{gathered}
    \right].
  \end{align}
\end{strip}
\lipsum[3-6] % more filler text

\end{document}

enter image description here

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