[Tex/LaTex] algorithm with partial borders/frames

algorithmicxalgorithmspage-breakingrules

I use the algorithm float environment for pseudocode and want some algorithms to span two pages. That works fine with \algstore and \algrestore. However, I would like to omit these borders at the end of the first part of the algorithm and at the top of the continuing part.

Is there a way to remove them while keeping the remaining border lines?

What I have is something like:

\documentclass{article}
\usepackage{algorithm}
\usepackage{algcompatible}

\newcommand{\algoallowbreak}{\algstore{myalg}\end{algorithmic}\end{algorithm}
    \begin{algorithm}
    \begin{algorithmic}\algrestore{myalg}
}

\begin{document}

\begin{algorithm}[h]
\caption{Algorithm 1}
\begin{algorithmic}[1]
    \State $a \gets b$
    \State some other code

\algoallowbreak

    \State some code that could possibly be wrap onto the next side
\end{algorithmic}
\end{algorithm}

\end{document}

And I want to remove the both border lines between algorithm line 2 and 3.

enter image description here

Best Answer

Here's one possible solution; it requires for you to issue \BreakAlgo before an algorithmth that will have the new specifications:

\documentclass{article}
\usepackage{algorithm}
\usepackage{algcompatible}
\usepackage{etoolbox}

\makeatletter
\newcommand\fs@myruledtop{\def\@fs@cfont{\bfseries}\let\@fs@capt\floatc@ruled
  \def\@fs@pre{\hrule height.8pt depth0pt \kern2pt}%
  \def\@fs@post{\kern2pt}%
  \def\@fs@mid{\kern2pt\hrule\kern2pt}%
  \let\@fs@iftopcapt\iftrue}
\newcommand\fs@myruledbottom{\def\@fs@cfont{\bfseries}\let\@fs@capt\floatc@ruled
  \def\@fs@pre{\kern2pt}%
  \def\@fs@post{\kern2pt\hrule\relax}%
  \def\@fs@mid{}%
  \let\@fs@iftopcapt\iftrue}
\makeatother

\newif\ifalgobreak
\newif\ifalgobreaksecond

\newcommand\BreakAlgo{\algobreaktrue}

\AtBeginEnvironment{algorithm}{
\ifalgobreak
  \floatstyle{myruledtop}
  \restylefloat{algorithm}
\fi
\ifalgobreaksecond
  \floatstyle{myruledbottom}
  \restylefloat{algorithm}
\else
\fi
}

\AfterEndEnvironment{algorithm}{%
  \algobreakfalse\algobreaksecondfalse
  \floatstyle{ruled}
  \restylefloat{algorithm}%
}

\newcommand\algoallowbreak[1][]{%
  \algstore{myalg}
  \end{algorithmic}
  \end{algorithm}
  \algobreaksecondtrue
  \begin{algorithm}
  \begin{algorithmic}[#1]
  \algrestore{myalg}%
}

\begin{document}

\BreakAlgo
\begin{algorithm}[h]
\caption{Algorithm 1}
\begin{algorithmic}[1]
\State $a \gets b$
\State some other code

\algoallowbreak

\State some code that could possibly be wrap onto the next side
\end{algorithmic}
\end{algorithm}

\begin{algorithm}[h]
\caption{Algorithm 2}
\begin{algorithmic}[1]
    \State $a \gets b$
    \State some other code
\end{algorithmic}
\end{algorithm}

\end{document}

enter image description here

The idea was to define two new styles for algorithms (one suppressing the bottom rule, the other one, suppressing the top rule) and applying these new styles conditionally depending on \BreakAlgo

I also added an optional argument to \algoallowbreak so as to specify numbering in the continuation part; notice that this fixes the alignment problem you had in your original settings for the continuation. If the numbering will always be present, you don't need the optional argument and in this case the definition would be

\newcommand\algoallowbreak{%
  \algstore{myalg}
  \end{algorithmic}
  \end{algorithm}
  \algobreaksecondtrue
  \begin{algorithm}
  \begin{algorithmic}[1]
  \algrestore{myalg}%
}

And then, in your document:

\BreakAlgo
\begin{algorithm}[h]
\caption{Algorithm 1}
\begin{algorithmic}[1]
\State $a \gets b$
\State some other code

\algoallowbreak

\State some code that could possibly be wrap onto the next side
\end{algorithmic}
\end{algorithm}

Explanation

To match your first two requests, I've redefined the behavior of for to have an end statement by adding the lines:

\algdef{SE}{For}{End}[2]{%
  \textkeyword{for} \(#1\) \textkeyword{to} \(#2\) \textkeyword{do begin}}{%
  \textkeyword{end}}

To match your last request, it suffices to add the line:
```
\algrenewcommand\textkeyword{\textrm}
```
which redefines the font for keywords to be \textrm instead of \textbf.
In regards of your 3rd request, there are two ways.
- If you want the algorithm to behave as an algorithm, simply load the algorithm package with the option plain as in the above MWE:
```
\usepackage[plain]{algorithm}
```
- If you want the algorithm to behave as a figure, there is no need to load the algorithm package, simply insert the algorithmic environment inside a figure, i.e. replace the lines
```
\begin{algorithm}
\begin{algorithmic}[1]
...
\end{algorithmic}
\caption{Paull's algorithm}
\end{algorithm}
```
  with
```
\begin{figure}
\begin{algorithmic}[1]
...
\end{algorithmic}
\caption{Paull's algorithm}
\end{figure}
```
  and you will have

Addendum

This is the complete implementation of the algorithm in the figure:

\documentclass{article}
\usepackage[plain]{algorithm}
\usepackage{algpascal}

\begin{document}

\algrenewcommand\textkeyword{\textrm}
\algdef{SE}{For}{End}[2]{%
  \textkeyword{for} \(#1\) \textkeyword{to} \(#2\) \textkeyword{do begin}}{%
  \textkeyword{end}}
\algdef{SE}{ForEach}{End}[1]{%
  \textkeyword{for each} #1 \textkeyword{do begin}}{%
  \textkeyword{end}}

\begin{algorithm}
\begin{algorithmic}[1]
\State Assign an ordering $A_{1}, \dots, A_{n}$ to the nonterminals of the grammar.
\For{i := 1}{n}
    \For{j := 1}{i-1}
        \ForEach{production of the form $A_{i} \rightarrow A_{j} \alpha$}
            \State remove $A_{i} \rightarrow A_{j} \alpha$ from the grammar
            \ForEach{production of the form $A_{j} \rightarrow \beta$}
                \State add $A_{i} \rightarrow \beta\alpha$ to the grammar
            \End
        \End
    \End
    \State transform the $A_{i}$-productions to eliminate direct left recursion
\End
\end{algorithmic}
\caption{Paull's algorithm}
\end{algorithm}

\end{document}

enter image description here

There is the need to define a new command \ForEach:

\algdef{SE}{ForEach}{End}[1]{%
  \textkeyword{for each} #1 \textkeyword{do begin}}{%
  \textkeyword{end}}

Note that I've defined \ForEach so to take one "text" argument, because it seemed to me the best way to define it.

If you want it to take a "math" argument, then define it as

\algdef{SE}{ForEach}{End}[1]{%
  \textkeyword{for each} \(#1\) \textkeyword{do begin}}{%
  \textkeyword{end}}

and use it as follows (amsmath is needed for the command \text):

\ForEach{\text{production of the form }A_{i} \rightarrow A_{j} \alpha}

Best Answer

Related Solutions

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Explanation

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