How to put a figure on the top of a page on its own in latex?

One of the figures appear in the middle of a page (on 开发者_JS百科its own) when the figure does not fit the other text. How to show it on top of the new page?

If all else fails, just add \vspace*{3in} to the bottom of your figure below the \caption. Then by trial and error change the 3in dimension until you get the look you want. This is of course pure brute force, but sometimes that's a lot easier than trying to get LaTeX to do things the "right" way.

When in doubt, use brute force.

--- Ken Thompson

I think I misunderstood your question. Are you asking "how do I get floats on pages by themselves to be at the top of the page, rather than vertically centred?"?.

If so, here's how to customise the float page. From source2e, glue is inserted at the top and bottom of the page, and between each float on the page. This inserted glue is given by the following parameters:

\setlength\@fptop{0\p@ \@plus 1fil} 
\setlength\@fpsep{8\p@ \@plus 2fil} 
\setlength\@fpbot{0\p@ \@plus 1fil}

Simply redefine these to get the output you like. For example, for top- and bottom- aligned floats: (untested)

\makeatletter
\setlength\@fptop{0pt} 
\setlength\@fpsep{8pt plus 1fil} 
\setlength\@fpbot{0pt}
\makeatother

You can insert a pagebreak via \clearpage or \newpage, then use the t option on the figure environment:

...

\clearpage

\begin{figure}[t!]
    \centering
    \includegraphics[scale=.75]{graphic/...}
    \caption{}
    \label{fig:}    
\end{figure}

...

If there's nowhere for the figure to fit then it will go on a page by itself. See the FAQ answer on floats for more information on how to customise this behaviour.