How can I use one column in the proc document class?

Question

I'm making a 5 pages report about this year's activities. Using the proceedings document class I managed to get very close to the format I've been required to use, but I just can't make it to work with only one column! How can I make a one column document using the proc document class? if I use:

\documentclass[letterpaper,10pt,onecolumn]{proc}

I get this error:

! Class proc Error: Option `onecolumn' not supported.

the beggining of the document is:

\documentclass[letterpaper,10pt]{proc}
\usepackage{fancyhdr}

\pagestyle{fancy}
\fancyhead{}
\fancyfoot{}
\fancyhead[C]{my header}  
\fancyfoot[C]{\thepage}

\renewcommand{\headrulewidth}{0.5pt}

%opening
\title{ bla bla bla }

\author{ me }

\begin{document}
\onecolumn

\maketitle

document bla bla bla

Answer 1

Here is a brief mockup of a possible switch to the article document class. A comparison to what your MWE compiled under the proc document class is also provided.

\documentclass[10pt]{article}
\usepackage{lipsum}% http://ctan.org/pkg/lipsum
\usepackage{calc}% http://ctan.org/pkg/calc
\usepackage[
  letterpaper,%
  textheight={47\baselineskip+\topskip},%
  textwidth={\paperwidth-126pt},%
  footskip=75pt,%
  marginparwidth=0pt,%
  top={\topskip+0.75in}]{geometry}% http://ctan.org/pkg/geometry
\usepackage{fancyhdr}% http://ctan.org/pkg/fancyhdr

\pagestyle{fancy}
\fancyhead{} \fancyfoot{}% Clear header & footer
\fancyhead[C]{my header}% Set centered header
\fancyfoot[C]{\thepage}% Set centered footer
\renewcommand{\headrulewidth}{0.5pt}% Add header rule

% Titling
\title{ bla bla bla }% Your title
\author{ me }% Your author
\date{ \today }% Your date
\makeatletter
% Definition of proc.cls' \maketitle:
\def\@maketitle{% 
  \vbox to 2.25in{%
    \hsize\textwidth
    \linewidth\hsize
    \vfil
    \centering
    {\LARGE \@title \par}
    \vskip 2em
    {\large \begin{tabular}[t]{c}\@author \end{tabular}\par}
    \vfil}}
\makeatother
\begin{document}
\maketitle % Produce title
\thispagestyle{fancy}% Override titling page style with fancy

\lipsum[1-10]% Your document text
\end{document}

The layout is not 100% perfect in comparison with your original MWE, but I'm not sure how close you want to have them match. Some of the length choices were based on scanning proc.cls. You mentioned the spacing around the title. I copied the \@maketitle macro from proc and used it as-is in my MWE to produce the exact same spacing around the title. The only difference seems to be in the margins, which can be adjusted as needed via geometry's easy-to-use interface.

Additional packages included are: calc for infix length arithmetic, lipsum for dummy text creates (Lorem Ipsum style), geometry for page layout (margins, stock, text area, ...) formatting.

Answer 2

Issue \onecolumn immediately after \begin{document}.

Note: The small margins of the proc class are not at all suited for a one-column document with a font size of 10pt. You might want to increase the margins and/or the font size.

EDIT: In response to your edited question: \maketitle does indeed (for whatever reason) switch back to \twocolumn. In my updated example, I use the etoolbox package to selectively alter the definition of \maketitle. (Please consider to switch to the article class as suggested by Werner.)

\documentclass[letterpaper,10pt]{proc}

\usepackage{etoolbox}

\makeatletter
\patchcmd{\maketitle}{\twocolumn[\@maketitle]}{\@maketitle}{}{}
\makeatother

\title{bla bla bla}
\author{me}

\usepackage{lipsum}

\begin{document}

\onecolumn

\maketitle

\lipsum[1]

\end{document}