ieee-styleieeetranpositioningtwo-column
I'm trying to put a two-column wide figure on the first page of my manuscript to be submitted to IEEE conference. It seems that with IEEEconf.cls it doesn't allow me to do so. It always appears on the second page.
I'm wondering if it is somewhere mentioned that doing so is not permitted in IEEE.
You mention that very specific requirements for the document - only two pages, and a two-column format. The following minimal example duplicates this using the multicol package. It allows multiple column document format via the multicols environment that takes a mandatory argument:
\begin{multicols}{<n>}
...
\end{multicols}
This is an option in lieu of specifying a twocolumn document class option. As such, specifying your first image before starting the multicols environment, and specifying the second image after produces the desired result. The first image is still specified within a figure float with a float specifier of [b] (for bottom placement) while the last figure has a float specifier of [t] (for top placement):
\documentclass{article}
\usepackage{multicol}% http://ctan.org/pkg/multicol
\usepackage[demo]{graphicx}% http://ctan.org/pkg/graphicx
\usepackage{lipsum}% http://ctan.org/pkg/lipsum
\begin{document}
\begin{figure}[b]
\centering
\includegraphics{figure1}
\caption{This is the first figure}
\end{figure}
\begin{multicols}{2}
\lipsum[1-7]
\end{multicols}
\begin{figure}[t]
\centering
\includegraphics{figure2}
\caption{This is the second figure}
\end{figure}
\end{document}
In the above example, graphicx is loaded with the demo package option which replaces all images with a 150pt x 100pt black rectangle (for compatibility reason). You should remove this for your document. Also, lipsum was used to generate dummy text.
(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?
Best Answer
As @HarishKumar says, in general this is not possible, and will likely be rejected by the journal. Simply put the figure on the next page. There exists a very dirty trick that allows it, but it is a likely reason for rejection. The body of the article has to start by the first section and not by a figure!
It is probably not mentioned in the manual since (1) the class simply never does it and (2) it is the standard, you never have a figure before the body of the document, so the only figures that can appear on the first page are at the bottom of either column, or at the top of the second column (but only the second column).
Ad your comment: There is a way how to put it at the bottom of the first page, but wide bottom figures are discouraged in twocolumn articles. And the trick is a dirty trick that involves manual measurements and seriously manual tweaks. (And if you post an MWE which shows your wide figure at the top of page 2, I can modify it to make it appear at the bottom of page 1.)