Sectioning chapter, section, subsection formatting

Question

I'd like some help with the formatting of chapter, section and subsections.

I am using the report document class and I'd like to generate the following chapter, section and subsection formatting in the document.

Each (and only) chapter page should have a 2in top margin. Chapters, Section and Subsection title should have the same font size as text.

Then, the format should be as follows: Capital Roman Numbering for chapters, chapter title should be centered and display only the number dot the title of the chapter, i.e.

I. Introduction

Lower case roman numbering for section also centered and should display Chapter number dot Section Number dot Section title, i.e.

I.i. Section in Introduction chapter

And finally the subsection should not be numbered at all and left justified.

Answer 1

This is readily achievable using sectsty and some manual adjustments for the \chapter setting:

\documentclass{report}

\usepackage{sectsty}

% http://tex.stackexchange.com/q/59726/5764
\allsectionsfont{\centering\normalsize\bfseries}% All sections are centred/normal size/bold
\subsectionfont{\normalsize\bfseries}% Correct \subsection formatting

\renewcommand{\thechapter}{\Roman{chapter}}% Chapter number formatting
\renewcommand{\thesection}{\thechapter.\roman{section}}% Section number formatting

% http://tex.stackexchange.com/q/42161/5764
\setcounter{secnumdepth}{1}% Only number up to \section

\makeatletter
% http://tex.stackexchange.com/q/24439/5764
\renewcommand{\@seccntformat}[1]{\csname the#1\endcsname.~}% Add period after section number in title

% Taken from http://mirrors.ctan.org/macros/latex/contrib/sectsty/sectsty.dtx
\def\@makechapterhead#1{%
  \vspace*{2in}% Formerly \vspace*{50\p@}%
  {\parindent \z@ \raggedright \normalfont
    %\ifnum \c@secnumdepth >\m@ne
    %    \huge\bfseries\SS@chapnumfont{\@chapapp\space \thechapter}%
    %    \par\nobreak
    %    \vskip 20\p@
    %\fi
    \interlinepenalty\@M
    %\raggedright \normalfont
    \Huge \bfseries \SS@chaptitlefont {\thechapter.~#1}\par\nobreak
    \vskip 40\p@
  }}
\makeatother

\begin{document}

\chapter{A chapter}
Some text in this chapter.

\section{A section}
Some text in this section.

\subsection{A subsection}
Some text in this subsection.

\end{document}

The 2" margin for \chapter-pages only is measured from the top of the text block. As such, the regular text block margins relative to the page still remains.

References to other questions relating to the above changes are scattered within the code.