Update
KOMA-Script version 3.26 introduces two new keys to \RedeclareSectionCommand and \RedeclareSectionCommands: runin and afterindent. Possible values for both keys are bysign, true and false.
runin:
This key is only defined for sectioning commands with style=section, eg section, subsection, subsubsection, paragraph, subparagraph.
By default runin=bysign is set. Then the sign of afterskip decides if the heading is a runin heading (negative sign) or not (positive value) and the absolute value of afterskip is used for the horizontal or vertical skip after the heading. This is the same behavior as explained in the original answer below.
With runin=true it is a runin heading and the sign of afterskip has no meaning anymore. Note that the absolute value of afterskip is used as the horizontal skip. So even a negative value of afterskip will result in positive horizontal skip.
With runin=false it is a freestanding heading and the value of afterskip is used as vertical skip. Note that with runin=false a negative value of afterskip results in a negative vertical skip.
afterindent:
By default
afterindent=bysign is set for style=section and style=chapterafterindent=true is set for style=part and class scrartclafterindent=false is set for style=part and class scrbook
With afterindent=bysign the sign of beforeskip determines if the first line after the heading uses the paragraph indentation or not. With afterskip=bysign the absolute value of beforeskip is used as vertical skip above the heading. This is the same behavior as explained in the original answer below.
With afterindent=true the paragraph indentation is used for the first line following a freestanding heading. With afterindent=false this first line is not indented. With both afterindent=true or afterindent=false the value of beforeskip is used as the skip above the heading. So a negative value of beforeskip results in a negative skip, even for a runin heading.
Example:
\documentclass{scrreprt}
\RedeclareSectionCommand[
%runin=false,
afterindent=false,
beforeskip=0pt,
afterskip=2\baselineskip]{chapter}
\RedeclareSectionCommand[
%runin=false,
afterindent=false,
beforeskip=\baselineskip,
afterskip=.5\baselineskip]{section}
\RedeclareSectionCommand[
%runin=false,
afterindent=false,
beforeskip=.75\baselineskip,
afterskip=.5\baselineskip]{subsection}
\RedeclareSectionCommand[
%runin=false,
afterindent=false,
beforeskip=.5\baselineskip,
afterskip=.25\baselineskip]{subsubsection}
\RedeclareSectionCommand[
runin=true,
%afterindent=false,
beforeskip=.5\baselineskip,
afterskip=1em]{paragraph}
\RedeclareSectionCommand[
runin=true,
%afterindent=false,
beforeskip=.5\baselineskip,
afterskip=1em]{subparagraph}
\begin{document}
\chapter{Erde}
Der eigentliche Text.\par
Test
\section{Europa}
Der eigentliche Text.
\subsection{Italien}
Der eigentliche Text.
\subsubsection{Toskana}
Der eigentliche Text.
\paragraph{Florenz}
Der eigentliche Text.
\subparagraph{Dom}
Der eigentliche Text
\end{document}
Original answer
It is easy with the new macros \RedeclareSectionCommand and \RedeclareSectionCommands of the KOMA-Script version 3.15.
\documentclass{scrreprt}
\RedeclareSectionCommand[
beforeskip=-1sp,
afterskip=2\baselineskip]{chapter}
\RedeclareSectionCommand[
beforeskip=-\baselineskip,
afterskip=.5\baselineskip]{section}
\RedeclareSectionCommand[
beforeskip=-.75\baselineskip,
afterskip=.5\baselineskip]{subsection}
\RedeclareSectionCommand[
beforeskip=-.5\baselineskip,
afterskip=.25\baselineskip]{subsubsection}
\RedeclareSectionCommand[
beforeskip=.5\baselineskip,
afterskip=-1em]{paragraph}
\RedeclareSectionCommand[
beforeskip=-.5\baselineskip,
afterskip=-1em]{subparagraph}
\usepackage{blindtext}
\begin{document}
\chapter{Erde}
Der eigentliche Text.\par
Test
\section{Europa}
Der eigentliche Text.
\subsection{Italien}
Der eigentliche Text.
\subsubsection{Toskana}
Der eigentliche Text.
\paragraph{Florenz}
Der eigentliche Text.
\subparagraph{Dom}
Der eigentliche Text
\end{document}
beforeskip: The absolute value is the vertical space before the heading. If the value is negative the paragraph indent of the text following this heading is suppressed.
afterskip: A positive value is a vertical skip below the heading. A negative value activates a run-in heading. Then the absolute value is the horizontal skip.
There is also a command \RedeclareSectionCommands to change several section-like commands at once:
\documentclass{scrreprt}
\renewcommand*{\chapterheadstartvskip}{\vspace*{0cm}}
\renewcommand*{\chapterheadendvskip}{\vspace*{2\baselineskip}}
\RedeclareSectionCommands[
beforeskip=-.5\baselineskip,
afterskip=.25\baselineskip
]{section,subsection,subsubsection}
\RedeclareSectionCommands[
beforeskip=.5\baselineskip,
afterskip=-1em]{paragraph,subparagraph}
\begin{document}
\chapter{Erde}
Der eigentliche Text.\par
Test
\section{Europa}
Der eigentliche Text.
\subsection{Italien}
Der eigentliche Text.
\subsubsection{Toskana}
Der eigentliche Text.
\paragraph{Florenz}
Der eigentliche Text.
\subparagraph{Dom}
Der eigentliche Text
\end{document}
The result is the same as in the original answer.
With KOMA-Script version 3.14 you have to redefine the original commands (based on a suggestion by Markus Kohm). Note that the original definitions of this commands differ from KOMA-Script version to KOMA-Script version.
\documentclass[headings=small]{scrreprt}
\renewcommand*{\chapterheadstartvskip}{\vspace*{0cm}}
\renewcommand*{\chapterheadendvskip}{\vspace*{2\baselineskip}}
\makeatletter
%% check if this are the original definitions
\CheckCommand\section{%
\scr@startsection{section}{\sectionnumdepth}{\z@}%
{-3.5ex \@plus -1ex \@minus -.2ex}%
{2.3ex \@plus.2ex}%
{\ifnum \scr@compatibility>\@nameuse{scr@[email protected]}\relax
\setlength{\parfillskip}{\z@ plus 1fil}\fi
\raggedsection\normalfont\sectfont\nobreak\size@section}%
}
\CheckCommand\subsection{%
\scr@startsection{subsection}{\subsectionnumdepth}{\z@}%
{-3.25ex\@plus -1ex \@minus -.2ex}%
{1.5ex \@plus .2ex}%
{\ifnum \scr@compatibility>\@nameuse{scr@[email protected]}\relax
\setlength{\parfillskip}{\z@ plus 1fil}\fi
\raggedsection\normalfont\sectfont\nobreak\size@subsection
}%
}
\CheckCommand\subsubsection{%
\scr@startsection{subsubsection}{\subsubsectionnumdepth}{\z@}%
{-3.25ex\@plus -1ex \@minus -.2ex}%
{1.5ex \@plus .2ex}%
{\ifnum \scr@compatibility>\@nameuse{scr@[email protected]}\relax
\setlength{\parfillskip}{\z@ plus 1fil}\fi
\raggedsection\normalfont\sectfont\nobreak\size@subsubsection
}%
}
%% redefine
\renewcommand\section{%
\scr@startsection{section}{\sectionnumdepth}{\z@}%
{-.5\baselineskip}%
{.25\baselineskip}%
{\ifnum \scr@compatibility>\@nameuse{scr@[email protected]}\relax
\setlength{\parfillskip}{\z@ plus 1fil}\fi
\raggedsection\normalfont\sectfont\nobreak\size@section}%
}
\renewcommand\subsection{%
\scr@startsection{subsection}{\subsectionnumdepth}{\z@}%
{-.5\baselineskip}%
{.25\baselineskip}%
{\ifnum \scr@compatibility>\@nameuse{scr@[email protected]}\relax
\setlength{\parfillskip}{\z@ plus 1fil}\fi
\raggedsection\normalfont\sectfont\nobreak\size@subsection
}%
}
\renewcommand\subsubsection{%
\scr@startsection{subsubsection}{\subsubsectionnumdepth}{\z@}%
{-.5\baselineskip}%
{.25\baselineskip}%
{\ifnum \scr@compatibility>\@nameuse{scr@[email protected]}\relax
\setlength{\parfillskip}{\z@ plus 1fil}\fi
\raggedsection\normalfont\sectfont\nobreak\size@subsubsection
}%
}
\makeatother
\begin{document}
\chapter{Erde}
Der eigentliche Text.\par
Test
\section{Europa}
Der eigentliche Text.
\subsection{Italien}
Der eigentliche Text.
\subsubsection{Toskana}
Der eigentliche Text.
\paragraph{Florenz}
Der eigentliche Text.
\subparagraph{Dom}
Der eigentliche Text
\end{document}
