SOLVED: lyx numbering equations by section

Question

i can not get numbering my equations by sections to work.  i added this
\numberwithin{equation}{section}
to the Document->Settings-> Latex preamble.  when i try to view the documents using dvi i get the following message
Undefined control sequence.
Latex Error: Missing \begin{document}
here is a copy of my /home/user_name_here/.lyx/templates/defaults.lyx
#LyX 1.5.2 created this file. For more info see http://www.lyx.org/
\lyxformat 276
\begin_document
\begin_header
\textclass article
\begin_preamble
\numberwithin{equation}{section}
\end_preamble
\language english
\inputencoding auto
\font_roman default
\font_sans default
\font_typewriter default
\font_default_family sfdefault
\font_sc false
\font_osf false
\font_sf_scale 100
\font_tt_scale 100
\graphics default
\paperfontsize default
\spacing single
\papersize a4paper
\use_geometry false
\use_amsmath 1
\use_esint 1
\cite_engine basic
\use_bibtopic false
\paperorientation portrait
\secnumdepth 3
\tocdepth 3
\paragraph_separation indent
\defskip medskip
\quotes_language english
\papercolumns 1
\papersides 1
\paperpagestyle default
\tracking_changes false
\output_changes false
\author ""
\author ""
\end_header
\begin_body
\begin_layout Standard
\end_layout
\end_body
\end_document
any ideas?
EDIT: found the answer to my question i needed to change Document->Settings->Math options
from "Use AMS math package automatically"  change that to "Use AMS math package"
Last edited by delacruz (2008-07-04 00:26:50)

Answer 1

My commands are kind of kludgy (they make the indenting a little weird), but I think they should work
First, we redefine the command used for numbering sections to "hspace*{-18pt} (ie: just display the title 18pts left of where it should  be). This may need to be adjusted depending on font size/ etc.
Next, we redefine the command used for numbering subsections to display the subsection number as an arabic numeral.
\renewcommand{\thesection}{\hspace*{-18pt}}
\renewcommand{thesubsection}{\indent\arabic{subsection}}
Just for reference, I believe the default behaviour is
\renewcommand{\thesection}{\arabic{section}}
\renewcommand{\thesubsection}{\arabic{section}.\arabic{subsection}
EDIT:
These commands should be placed in the preamble, although I think they work in document.
Also,
\renewcommand{\thesection}{\hspace*{-1.0em}}
\renewcommand{thesubsection}{\indent\arabic{subsection}}
may work better, depending on the font/ fontsize you use. (1.0em is roughly the width of an 'M' in the current font.)
Last edited by leocp1 (2012-01-16 17:55:30)