# Re: Formatting numbered equations

On 04/19/2010 02:25 PM, Marshall Feldman wrote:

Hello,

I have several questions regarding numbered equations:

1. How does one add punctuation to numbered equations?
2. How does one make the equations be part of a paragraph that begins
before and continues after them?
3. How does one continue a numbered equation across multiple lines?


That's a lot of questions. ;-)


For example:

_____________________________________________________________________________

Three of the most often quoted elementary mathematical
equations are

2 + 2 = 4                                        (1),
C = 2 x pi x r                                  (2), and
A = (1/2) b x h                               (3).

As you can see, Equation 2 is the most complex.


_____________________________________________________________________________ In the above example, I can't figure out how to add the commas, period, and conjunction adjacent to the equation numbers.


If you're using an equation array or something of the sort to format this, then you cannot add punctuation after the labels. There simply isn't any way to do this, so far as I know, not unless you define (or find) your own environments that allow it. An option is to turn on the "fleqn" option by putting "fleqn" in the Options field under Document>Settings>Document Class>Custom. This moves the numbers to the left, and then you can add the text in the usual way. Alternatively, change your syntax. "These are three...:".


Also notice that the sentence beginning with "As" is part of the paragraph beginning with "Three." I can't get Lyx to format them right. The sentence beginning with "Three" is indented because it starts a paragraph. When I add anything after an equation number, LyX automatically treats it as a new paragraph. So in the above example, the line beginning with "As you can" is treated as the start of a new paragraph and indented.


I'm not sure I fully understand this, but compare the two paragraphs in the attached document. In the second case, where the paragraph is indented, there is a return after the formula. If you put the cursor at the beginning of "what" and backspace, you will delete that return.


Regarding my third question, I have a long equation that should span multiple lines. Instead, LyX keeps it on one line that runs off the right side of the page, when it should look like:

5 = 1 + 5 = 2 + 3 = 3 + 2 = 4 + 1 = 10/2
= 50/10 = 100/20                               (4)


You'll have to use something like the gather environment, or maybe an align environment, to format this correctly. Example in the file, again.

rh


#LyX 1.6.6svn created this file. For more info see http://www.lyx.org/
\lyxformat 345
\begin_document
\textclass paper
\begin_preamble
\usepackage{heck}
\end_preamble
\use_default_options false
\language english
\inputencoding auto
\font_roman times
\font_sans helvet
\font_typewriter courier
\font_default_family default
\font_sc false
\font_osf false
\font_sf_scale 100
\font_tt_scale 100

\graphics default
\paperfontsize 11
\spacing single
\use_hyperref false
\papersize letterpaper
\use_geometry false
\use_amsmath 1
\use_esint 0
\cite_engine natbib_authoryear
\use_bibtopic false
\paperorientation portrait
\leftmargin 1in
\topmargin 1in
\rightmargin 1in
\bottommargin 1in
\secnumdepth 3
\tocdepth 3
\paragraph_separation indent
\defskip smallskip
\quotes_language english
\papercolumns 1
\papersides 1
\paperpagestyle plain
\tracking_changes false
\output_changes false
\author ""
\author ""

\begin_body

\begin_layout Standard
this.
\begin_inset Formula \begin{gather}
a=b\\
b=a\end{gather}

\end_inset

that.
and now more
\begin_inset Formula \begin{gather}
a=b\\
b=a\end{gather}

\end_inset

\end_layout

\begin_layout Standard
what happened? Uh oh.
\begin_inset Formula $a=b=c=d=e=f=g=h=i=j=k=l=m=n=o=p=q=r=s=t=u=v=w=x=y=z=0=1=2=3=4=5=6=7=8=9=0$

\end_inset

Let's fix that.
\begin_inset Formula \begin{align*}
a & =b=c=d=e=f=g=h=i=j=k=l\\
& =m=n=o=p=q=r=s=t=u=v=w\\
& =x=y=z=0=1=2=3=4=5=6=7=8=9=0\end{align*}

\end_inset

Much better.
\end_layout

\end_body
\end_document