How to tidy the equation in overleaf

Question

I would like to write two equations (R3 and R4) in overleaf.

Since I use a template which are in two column format, the equations become untidy as in the screenshot.

Here is the code:

\begin{equation} \label{eq:R3}
R_3(i) = 
 \begin{cases} 
  (q_i.c_i + (1-q_i)p_i + (n+1)w + nv)(\frac{q_i}{m_i-z_i} +\frac{(1-q_i)}{m_i-z_i})  & \text{if } i \geq (n-1) \\
  (q_n.p_n + (1-q_n)c_n + (n+1)w + nv)(\frac{q_n}{m_n-z_n} +\frac{(1-q_n)}{m_n-z_n})       & \text{if } i = n
 \end{cases}\end{equation}

\begin{equation} \label{eq:R4}
R_4(i) = 
 \begin{cases} 
  (q_i.p_i + (1-q_i)c_i + (n+3)w + (n+2)v)(\frac{q_i}{z_i+1} +\frac{(1-q_i)}{z_i+1})  & \text{if } i \geq (n-1) \\
  (q_n.c_n + (1-q_n)p_n + (n+3)w + (n+2)v)(\frac{q_n}{z_n+1} +\frac{(1-q_n)}{z_n+1})       & \text{if } i = n
 \end{cases}\end{equation}

Then, here is the preview.

Do you have any idea how to make these equations tidier ? I am thinking to make the font smaller however I am not sure what to do.

Thank you.

Answer 1

wrap and small fontsize

\documentclass{IEEEtran}
\usepackage{tabularray}
\usepackage{amsmath}
\usepackage{showframe}
\usepackage{lipsum}
\begin{document}
\lipsum[1-6]
\begin{equation}\label{eq:R3}
\small
R_3(i) =
\begin{cases}
\begin{tblr}{colspec={l},colsep={0pt}}(q_i.c_i + (1-q_i)p_i + (n+1)w + nv) \\ \times(\frac{q_i}{m_i-z_i} +\frac{(1-q_i)}{m_i-z_i})\end{tblr} & \text{if } i \geq (n-1) \\
\begin{tblr}{colspec={l},colsep={0pt}}(q_n.p_n + (1-q_n)c_n + (n+1)w + nv) \\ \times(\frac{q_n}{m_n-z_n} +\frac{(1-q_n)}{m_n-z_n})\end{tblr} & \text{if } i = n
\end{cases}
\end{equation}

\begin{equation}\label{eq:R4}
\footnotesize
R_4(i) =
\begin{cases}
\begin{tblr}{colspec={l},colsep={0pt}}(q_i.p_i + (1-q_i)c_i + (n+3)w + (n+2)v) \\ \times(\frac{q_i}{z_i+1} +\frac{(1-q_i)}{z_i+1})\end{tblr} & \text{if } i \geq (n-1) \\
\begin{tblr}{colspec={l},colsep={0pt}}(q_n.c_n + (1-q_n)p_n + (n+3)w + (n+2)v) \\ \times(\frac{q_n}{z_n+1} +\frac{(1-q_n)}{z_n+1})\end{tblr} & \text{if } i = n
\end{cases}
\end{equation}
\par\lipsum[1]
\end{document}

double column equation

\documentclass{IEEEtran}
\usepackage{cuted}
\usepackage{amsmath}
\usepackage{showframe}
\usepackage{lipsum}
\begin{document}
\lipsum[1-2]
\begin{strip}
\begin{equation}\label{eq:R3}
R_3(i) =
\begin{cases}
(q_i.c_i + (1-q_i)p_i + (n+1)w + nv)(\frac{q_i}{m_i-z_i} +\frac{(1-q_i)}{m_i-z_i}) & \text{if } i \geq (n-1) \\
(q_n.p_n + (1-q_n)c_n + (n+1)w + nv)(\frac{q_n}{m_n-z_n} +\frac{(1-q_n)}{m_n-z_n}) & \text{if } i = n
\end{cases}
\end{equation}
\begin{equation}\label{eq:R4}
R_4(i) =
\begin{cases}
(q_i.p_i + (1-q_i)c_i + (n+3)w + (n+2)v)(\frac{q_i}{z_i+1} +\frac{(1-q_i)}{z_i+1}) & \text{if } i \geq (n-1) \\
(q_n.c_n + (1-q_n)p_n + (n+3)w + (n+2)v)(\frac{q_n}{z_n+1} +\frac{(1-q_n)}{z_n+1}) & \text{if } i = n
\end{cases}
\end{equation}
\end{strip}
\lipsum[4-7]
\end{document}

Answer 2

Typesetting such big formulas in two-column format often requires some comprimise.

Here the compromise is to split the longish parts and give up with cases, so pushing the conditions under the longer top part.

Using newtxmath not only ensures consistency between text and math fonts, but also makes the math narrower.

Note. showframe and lipsum are used only for debugging. The former adds the frames as seen in the picture.

\documentclass[journal]{IEEEtran}
\usepackage{amsmath,mathtools}
\usepackage{newtxtext,newtxmath}

\usepackage{showframe,lipsum}

\begin{document}

\lipsum*[1][1-3]
\begin{align}
\label{eq:R3}
\hspace{-0.5em}
R_3(i) &=
  \left\lbrace
  \begin{aligned}
    &\mathmakebox[0.5\columnwidth][l]{(q_i.c_i + (1-q_i)p_i + (n+1)w + nv)} \\[0.5ex]
    &\cdot\left(\frac{q_i}{m_i-z_i} +\frac{1-q_i}{m_i-z_i}\right)
    && \text{if } i \geq n-1
  \\[2ex]
    &\mathmakebox[0.5\columnwidth][l]{(q_n.p_n + (1-q_n)c_n + (n+1)w + nv)} \\[0.5ex]
    &\cdot\left(\frac{q_n}{m_n-z_n} +\frac{1-q_n}{m_n-z_n}\right)
    && \text{if } i = n
  \end{aligned}
  \right.
\\
\label{eq:R4}
\hspace{-0.5em}
R_4(i) &=
  \left\lbrace
  \begin{aligned}
    &\mathmakebox[0.5\columnwidth][l]{(q_i.p_i + (1-q_i)c_i + (n+3)w + (n+2)v)} \\[0.5ex]
    &\cdot\left(\frac{q_i}{z_i+1} +\frac{1-q_i}{z_i+1}\right)
    && \text{if } i \geq n-1
  \\[2ex]
    &\mathmakebox[0.5\columnwidth][l]{(q_n.c_n + (1-q_n)p_n + (n+3)w + (n+2)v)} \\[0.5ex]
    &\cdot\left(\frac{q_n}{z_n+1} +\frac{1-q_n}{z_n+1}\right)
    && \text{if } i = n
  \end{aligned}
  \right.
\end{align}
\lipsum

\end{document}

Answer 3

I'd like to suggest that you load the mathtools package -- a superset of the amsmath package -- and employ \mathrlap wrappers and dcases environments, both provided by the mathtools package.

\documentclass[journal]{IEEEtran} 
\usepackage{mathtools}   % for '\mathrlap' macro and 'dcases' env.
\usepackage{newtxtext,newtxmath} % Times Roman text and math font clones
\usepackage{lipsum}      % filler text
\begin{document}
\lipsum[1] % a paragraph of filler text
\begin{align} 
R_3(i) &=
 \begin{dcases}
  \mathrlap{\bigl(q_i c_i + (1-q_i)p_i + (n+1)w + nv\bigr)} \\
  \quad\times\biggl(\frac{q_i}{m_i-z_i} +\frac{1-q_i}{m_i-z_i}\biggr)
  & \text{if $1\le i<n$} \\[1ex]
  \mathrlap{\bigl(q_n p_n + (1-q_n)c_n + (n+1)w + nv)} \\
  \quad\times\biggl(\frac{q_n}{m_n-z_n} +\frac{1-q_n}{m_n-z_n}\biggr)
  & \text{if $i=n$}
 \end{dcases} \label{eq:R3} \\[1.5ex]
R_4(i) &=
 \begin{dcases}
  \mathrlap{\bigl(q_i p_i + (1-q_i)c_i + (n+3)w + (n+2)v\bigr)} \\
  \quad\times\biggl(\frac{q_i}{z_i+1} +\frac{1-q_i}{z_i+1}\biggr)
  & \text{if $1\le i<n$} \\[1ex]
  \mathrlap{\bigl(q_n c_n + (1-q_n)p_n + (n+3)w + (n+2)v\bigr)}\\
  \quad\times\biggl(\frac{q_n}{z_n+1} +\frac{1-q_n}{z_n+1}\biggr)
  & \text{if $i=n$}
 \end{dcases} \label{eq:R4}
\end{align}
\lipsum % more filler text
\end{document}