Adjusting the postion of chapter numbers in the Tufte-Latex class

Question

I'm using the Tufte-latex book class, and trying to figure out how to use numbers in the chapters/sections.

The default style has no numbers, which I turned off by commenting out this line:

% Turn off section numbering
%\setcounter{secnumdepth}{-1}

But I can't figure out how to make the Chapter Number, and Chapter Title be on the same line. At the moment the chapter title is underneath the number like so:

while I would prefer the chapter to look more like other sections, e.g.:

I've read through the class file a few times, but I'm not sure what I should be looking for as I'm not familiar with many of the commands. I think this section may be relevant, but am not certain:

(lines 1526 - 1534)

% Make Tuftian-style section headings and TOC formatting

\titleformat{\chapter}%
  [display]% shape
  {\relax\ifthenelse{\NOT\boolean{@tufte@symmetric}}{\begin{fullwidth}}{}}% format applied to label+text
  {\itshape\huge\thechapter}% label
  {0pt}% horizontal separation between label and title body
  {\huge\rmfamily\itshape}% before the title body
  [\ifthenelse{\NOT\boolean{@tufte@symmetric}}{\end{fullwidth}}{}]% after the title body

And possibly this part:

\titlespacing*{\chapter}{0pt}{50pt}{40pt} 

I would appreciate any guidance about how to tweak this.

Answer 1

You found the relevant section, the display option is causing this numbering style. Change it for example to hang to get a hanging label, such as with \section.

titlesec is the package providing such headings. The manual explains options and syntax.

Besides the command reference for \titleformat and \titlesection this documentation provides a set of examples in its appendix, which produce the well known appearance of standard LaTeX headings. This is a great start for starting customizing headings.

You can also make it similar to the \titleformat{\section} lines in the class file, just changing sizes and spacing.

Keep in mind, if you copy commands from a class file for using in your own preamble, use \makeatletter before and \makeatotherafterwards, if a macro contains an @ symbol.

Answer 2

Since Forkrul Assail's request wasn't answered, I tried to solve it myself. I ended up copying the definition from tufte-common.def and adjusting it with the [block]-shape instead of [display] and increasing the horizontal separator from 0pt to 1em. So I put the following in my preamble:

  \titleformat{\chapter}
  [block]% shape
  {\relax\ifthenelse{\NOT\boolean{@tufte@symmetric}}{\begin{fullwidth}}{}}% format applied to label+text
  {\itshape\huge\thechapter}% label
  {1em}% horizontal separation between label and title body
  {\huge\rmfamily\itshape}% before the title body
  [\ifthenelse{\NOT\boolean{@tufte@symmetric}}{\end{fullwidth}}{}]% after the title body

Ending up with this:

If someone comes here and wonders how to get chapter numbers you just need

\setcounter{secnumdepth}{0}

in your preamble.