latex 写伪代码

\begin{algorithm}[htb]
  \caption{ Framework of ensemble learning for our system.}
  \label{alg:Framwork}
  \begin{algorithmic}[1]
    \Require
      The set of positive samples for current batch, $P_n$;
      The set of unlabelled samples for current batch, $U_n$;
      Ensemble of classifiers on former batches, $E_{n-1}$;
    \Ensure
      Ensemble of classifiers on the current batch, $E_n$;
    \State Extracting the set of reliable negative and/or positive samples $T_n$ from $U_n$ with help of $P_n$;
    \label{code:fram:extract}
    \State Training ensemble of classifiers $E$ on $T_n \cup P_n$, with help of data in former batches;
    \label{code:fram:trainbase}
    \State $E_n=E_{n-1}cup E$;
    \label{code:fram:add}
    \State Classifying samples in $U_n-T_n$ by $E_n$;
    \label{code:fram:classify}
    \State Deleting some weak classifiers in $E_n$ so as to keep the capacity of $E_n$;
    \label{code:fram:select} \\
    \Return $E_n$;
  \end{algorithmic}
\end{algorithm}