titlesec 格式

Question

\documentclass[12pt,letterpaper]{report}
\usepackage{blindtext}
\usepackage[utf8]{inputenc}
\usepackage[margin=1in,showframe]{geometry}
\usepackage{titlesec}


\titleformat{<command>}[<shape>]{<format>}{<label>}{<sep>}{<before-code>}[<after-code>]
\titlespacing{<command>}{<left>}{<before-sep>}{<after-sep>}

\begin{document}


\chapter{INTRODUCTION}

This is the first section.

Lorem  ipsum  dolor  sit  amet,  consectetuer  adipiscing  
elit.   Etiam  lobortisfacilisis sem.  Nullam nec mi et 
neque pharetra sollicitudin.  Praesent imperdietmi nec ante. 
Donec ullamcorper, felis non sodales...

我如何使用 titlesec 包来执行此操作我应该输入什么：

 \titleformat{<command>}[<shape>]{<format>}{<label>}{<sep>}{<before-code>}[<after-code>]

和：

  \titlespacing{<command>}{<left>}{<before-sep>}{<after-sep>}

Answer 1

类似这样的事？

\titleformat{\chapter}[display]
    {\filcenter\normalfont\Large\bfseries}
    {\MakeUppercase{\chaptertitlename}\ \thechapter}
    {20pt}
    {}
\titlespacing*{\chapter}{0pt}{0.7in}{20pt}

我有点不明白double space。我用过20pt，但你可以用\baselineskip代替20pt。

\documentclass[12pt,letterpaper]{report}
\usepackage{blindtext}
\usepackage[utf8]{inputenc}
\usepackage[margin=1in,showframe]{geometry}
\usepackage{titlesec}


\titleformat{\chapter}[display]
    {\filcenter\normalfont\Large\bfseries}
    {\MakeUppercase{\chaptertitlename}\ \thechapter}
    {20pt}
    {}
\titlespacing*{\chapter}{0pt}{0.7in}{20pt}

\begin{document}


\chapter{INTRODUCTION}

This is the first section.

Lorem  ipsum  dolor  sit  amet,  consectetuer  adipiscing
elit.   Etiam  lobortisfacilisis sem.  Nullam nec mi et
neque pharetra sollicitudin.  Praesent imperdietmi nec ante.
Donec ullamcorper, felis non sodales...
\end{document}