Center figure which spans over whole page

Question

I would like to get this to center with 5pt margins on left, right, and top. So the picture will cover nearly the whole page with room at the bottom for captions.

\documentclass{article}
\usepackage{tikz}
\usepackage{caption}

\begin{document}
\begin{centering}
\begin{figure}[ht]


\begin{tikzpicture}[scale=(3/10)]

  \draw[help lines] (0,0) grid (600mm,500mm);

\end{tikzpicture}

\caption{some caption here}
\end{figure}
\clearpage
\end{centering}
\end{document}

Answer 1

Here's a combination of Stefan's and Matthew's answer. Both of them addressed one of the points needed to solve your problem. To get 5pt margins on left, right, and top, use

\usepackage[left=5pt,top=5pt,right=5pt]{geometry}

For centering, put \centering inside the figure environment (just as Stefan wrote). A complete example:

\documentclass{article}
\usepackage[left=5pt,top=5pt,right=5pt]{geometry}
\usepackage{tikz}
\usepackage{caption}

\begin{document}
\begin{figure}[ht]
\centering
\begin{tikzpicture}[scale=(3/10)]
  \draw[help lines] (0,0) grid (600mm,500mm);
\end{tikzpicture}
\caption{some caption here}
\end{figure}
\end{document}

Now this does not cover nearly the whole page. For this you have to change the scale of your tikzpicture or increase the values 600mm and 500mm accordingly.

As Matten wrote in his answer, this is only a good idea for single pages. If you want to do something like this in a larger document, then you can use Stefan's answer to the question I linked to in a comment above:

\begin{figure}[ht]
\noindent
\makebox[\textwidth]{
  \begin{tikzpicture}[scale=(3/10)]
    \draw[help lines] (0,0) grid (600mm,500mm);
  \end{tikzpicture}
}
\caption{some caption here}
\end{figure}

Answer 2

It's not centering because your tikzpicture is wider than than the text width, resulting in an overfull \hbox. You can use the geometry package to change the margins.

Answer 3

A completely different solution using absolute positioning with TikZ (this needs two compilations to show up in the correct position)

\documentclass{article}
\usepackage{tikz,caption}
\usetikzlibrary{calc}

\begin{document}
\clearpage
\thispagestyle{empty}
\begin{tikzpicture}[overlay,remember picture]
    \draw ($(current page.south west)+(5pt,0.5cm)$) grid ($(current page.north east)-(5pt,5pt)$);
    \node[anchor=base,inner sep=0cm] at (current page.south) {\parbox{\textwidth}{\captionof{figure}{The Grid}}};
\end{tikzpicture}
\clearpage
\end{document}

Of course your actual picture must be drawn in reference to (current page), e.g. by transforming the canvas so that (0,0) is at (current page.center) or at the bottom left.

Answer 4

Yes, the figure is too wide.

A very simple approach is to calculate the hskip based on the scale and the width... It is not suitable for larger documents, but for a single page okay. There are ways to alter the page margins and text width...

\documentclass{article}
\usepackage{tikz}
\usepackage{caption}

\begin{document}
\begin{figure}[ht]

\vskip-30mm\hskip-29mm
\begin{tikzpicture}[scale=(3/10)]

  \draw[help lines] (0,0) grid (600mm,500mm);

\end{tikzpicture}

\caption{some caption here}
\end{figure}
\clearpage
\end{document}`

PS: centering with floating environments like figure should always take place inside the environment

Answer 5

Just use \centering inside the figure environment instead of outside. Such (list) environments don't have the desired effect on floating environments.

A remark: blank lines in the source code cause paragraph breaks. Your code has a lot of them, perhaps not all are intended to break paragraphs.