One-column wide figure in a two-column document goes to the last (4th) page, I want it at the top of 2nd page

Question

I am using following code to put a wide figure in a two column document. But it put the figure at the end of document

 \begin{figure*}
    \centering
    \includegraphics[width=\textwidth]{Structure_dimensions.eps}
    \caption{Dimensions of cube}
    \label{fig_dimensions}
 \end{figure*}

Question: How can I specify the placement of figure e.g. I want to put figure on top of second page and continue two column text beneath the figure.

Thanks in advance

Answer 1

(too long for a comment, hence posted as an answer)

As barbara beeton has already pointed out in a comment, LaTeX must "encounter" the code for the figure* environment before the start of the page on which the float is supposed to be placed. This condition is satisfied in the following example:

\documentclass[twocolumn]{article}
\usepackage{lipsum} % for filler text
\usepackage[demo]{graphicx} % omit 'demo' option in real doc.
\begin{document}

\lipsum[1-3] % filler text -- starts and ends on p. 1

\begin{figure*} % this float will be placed at top of p. 2
  \includegraphics[width=\textwidth]{Structure_dimensions.eps}
  \caption{Dimensions of cube}
  \label{fig_dimensions}
\end{figure*}

\lipsum[4-12] % more filler text -- starts on p. 1, continues to p. 2

\end{document}

The LaTeX kernel provides a parameter called \dbltopfraction; its default value is 0.7, which means that in a two-column document only up to 70% of the (top of the) page may be occupied by floats. Should your figure* env. be taller than this, LaTeX will either try to place the float on a page all by itself or, if that's somehow disabled, place the float at the end of the document. Is your figure* document possibly taller than 0.7\textheight?