Use headings in letters / vertical space

Question

I need to use headings in a letter, more precisely in documentclass dinbrief.

Knowing that LaTeX does not support section or subsection commands in this document class I use the following workaround:

\newcommand{\section}[1]{ { \huge \textbf{#1}} }
\newcommand{\subsection}[1]{ {\Large \textbf{#1}} }

The problem is that the vertical space is different if I compare both snippets below. Wherever, using the document class article with both methods, LaTeX uses the same space.

Method 1

\section{test}
Lorem ipsum dolor sit amet.

Method 2

\section{test}

Lorem ipsum dolor sit amet

Is there a better alternative to use headings — and if not, how to achieve the same vertical space?

Thank you.

Answer 1

If you want to reproduce the spacing from, say, the article class, you could more or less copy the definitions of the sectioning commands from article.cls, which use the LaTeX base macro \@startsection internally for typesetting of the title and appropriate spacing.

\documentclass{dinbrief}
\usepackage{lipsum}

\makeatletter
\setcounter{secnumdepth}{2}
\newcounter{section}
\newcounter{subsection}[section]
\renewcommand\thesection{\@arabic\c@section}
\renewcommand\thesubsection{\thesection.\@arabic\c@subsection}
\newcommand*\section{\@startsection{section}{1}{\z@}%
                    {-3.5ex \@plus -1ex \@minus -.2ex}%
                    {2.3ex \@plus.2ex}%
                    {\normalfont\huge\bfseries}}
\newcommand*\subsection{\@startsection{subsection}{2}{\z@}%
                       {-3.25ex\@plus -1ex \@minus -.2ex}%
                       {1.5ex \@plus .2ex}%
                       {\normalfont\Large\bfseries}}
\makeatother

\signature{Mr.\ Happy}

\begin{document}
  \begin{letter}{Mr.\ Grumpy}
    \opening{Hello,}
    \section{A Section}
    \lipsum[1]
    \subsection{A Subsection}
    \lipsum[2-3]
    \closing{Yours truly,}
  \end{letter}
\end{document}

I wasn't sure whether you also want section numbering. If not, just leave out the counter definitions or set secnumdepth to 0.

The arguments of \@startsection specify

1. the counter to be used for this level
2. the level of sectioning
3. the indentation for the heading
4. the vertical skip above the heading (a negative length means that the first paragraph of the section has no paragraph indentation, which doesn't make a difference in dinbrief)
5. the skip after the heading (if positive it's the vertical skip, if negative it's a horizontal skip and there's no linebreak after the heading, e.g. for \paragraph-like section levels)
6. and finally, the font used for the heading (here, I used the font sizes from your example, although it looks a bit huge IMO)

Of course, you can fiddle around with the lengths as you please. Also, I'm not sure whether dinbrief flushes the bottom of the page, so you might not even require rubber lengths for your spacing.

Edit:

You may also have to adjust the lengths in order to compensate for dinbrief's vertical paragraph spacing...