# the equation in the algorithm environment doesn't in the middle

I have the following problem: the equation in the algorithm doesn't in the middle of algorithm, how can I forward the equation, the code is as follows:

\begin{algorithm}[H]
\SetKwFor{KWHILE}{for}{do}{endfor}
\caption{algorithm }
\label{algo1} %
\KWHILE{stop condition}{
\begin{enumerate}[(a)]
\item sparse coding：problem$$\underset{{{\mathbf{x}}_{i}}}{\mathop{\min }}\,\left\| {{\mathbf{y}}_{i}}-{{\mathbf{D}}^{\left( J-1 \right)}}{{\mathbf{x}}_{i}} \right\|_{2}^{2}\ \ \ \ s.t.\ \ \ {{\left\| {{\mathbf{x}}_{i}} \right\|}_{0}}\le s$$ \\
\item dictionary update：...
\end{enumerate}}
\end{algorithm}


Can anyone help me with this?

• Doesn't... what? Align? Appear? – TheIncredibleZ1 Mar 21 '17 at 14:45
• Welcome to TeX.SE! Please tell us which packages need to be loaded in order to make your code compilable. Please also tell us which document class you use. – Mico Mar 21 '17 at 14:47
• In a list, I always put an equation inside a \parbox{\linewidth}, or possibly \hspace*{\dimexpr\linewidth-\textwidth}\parbox{\textwidth}. – John Kormylo Mar 21 '17 at 15:37
• You might want to read tex.stackexchange.com/questions/503/why-is-preferable-to – user36296 Mar 21 '17 at 16:50
• You can really spruce up your code... – Werner Mar 22 '17 at 0:25

I tried to guess what packages you use:

\documentclass{article}

% Show layout borders
\usepackage{showframe}

% \SetKwFor
\usepackage[boxed]{algorithm2e}

% \begin{enumerate}[(a)]
\usepackage{enumerate}

% \underset
\usepackage{mathtools}

\begin{document}

\begin{algorithm}[H]
\SetKwFor{KWHILE}{for}{do}{endfor}
\caption{algorithm }
\label{algo1} %
\KWHILE{stop condition}{
\begin{enumerate}[(a)]
\item sparse coding：problem
$$\underset{{{\mathbf{x}}_{i}}}{\mathop{\min }}\,\left\| {{\mathbf{y}}_{i}}-{{\mathbf{D}}^{\left( J-1 \right)}}{{\mathbf{x}}_{i}} \right\|_{2}^{2}\ \ \ \ s.t.\ \ \ {{\left\| {{\mathbf{x}}_{i}} \right\|}_{0}}\le s$$
\item dictionary update：...
\end{enumerate}
}
\end{algorithm}

\section*{Just the Equation}

$$\underset{{{\mathbf{x}}_{i}}}{\mathop{\min }}\,\left\| {{\mathbf{y}}_{i}}-{{\mathbf{D}}^{\left( J-1 \right)}}{{\mathbf{x}}_{i}} \right\|_{2}^{2}\ \ \ \ s.t.\ \ \ {{\left\| {{\mathbf{x}}_{i}} \right\|}_{0}}\le s$$

\section*{enumerate and Equation}

\begin{enumerate}[(a)]
\item sparse coding：problem
$$\underset{{{\mathbf{x}}_{i}}}{\mathop{\min }}\,\left\| {{\mathbf{y}}_{i}}-{{\mathbf{D}}^{\left( J-1 \right)}}{{\mathbf{x}}_{i}} \right\|_{2}^{2}\ \ \ \ s.t.\ \ \ {{\left\| {{\mathbf{x}}_{i}} \right\|}_{0}}\le s$$
\item dictionary update：...
\end{enumerate}

\end{document}


• Please indicate where the middle of the equation should be? (copy the picture above to your computer and use the software paint or similar or a pen if necessary)
• I also deleted \\ in the equation.