[vox-tech] latex help

[Peter Jay Salzman]

awesome.  shawn, i'm really glad you're on the list.   :-)

btw, \fder and \fpar are my own macros:

\def\fpar#1#2{\frac{\partial#1}{\partial#2}}
\def\fder#1#2{\frac{d#1}{d#2}}

they're implemented with \def because when i wrote them over 6 years
ago when i was only using pure tex.  i didn't know much about latex back
then.  :)

pete

begin Shawn P. Neugebauer <spn@ucdavis.edu> 
> replace "\noalign..." with:
> 
> \intertext{\rule{45pt}{0pt}\hrulefill\rule{30pt}{0pt}}
> 
> where you adjust the values "45" and "30" so that the line starts
> at the appropriate place on the left and right, respectively.  (if you
> didn't know about this trick, these are called struts: rules with
> 0 width--they take up space and adjust spacing but don't print
> anything).  as you probably know, you can get rid of the "*" if you want 
> equation numbering, and you can tag equations you do not want
> numbered by adding "\notag" to the end of the line (before "\\").
> you might need to play with the vertical spacing here (e.g.,
> get rid of the "5pt", insert a vertical strut on the rule line, etc.)
> to achieve the look you're looking for.
> 
> FYI--you didn't define \fpar, but i don't think it matters.
> 
> i'm sure there's a more elegant way of getting want you want,
> but this looks pretty good on my screen.
> 
> shawn.
> 
> On Wednesday 01 May 2002 10:40 pm, you wrote:
> > hey there,
> >
> > i'm trying to achieve this effect in latex (i'm adding two equations
> > together):
> >
> >
> >       a  =  b + f
> >       d  =  e + f
> >      ---------------
> >      a+d = b + e +f
> >
> > here's what i have:
> >
> > \begin{align*}
> > \left( \vec{p} \times \vec{A} \right)_k =& p_i A_j - p_j A_i = -i\hbar
> >   \fpar{A_j}{x_i} + A_j p_i - \left[ -i\hbar \fpar{A_i}{x_j} - A_i p_j
> > \right]\\ \left( \vec{p} \times \vec{A} \right)_k =& A_i p_j - A_j p_i
> > \\[5pt] %
> > \noalign{\hrule}\\[-5pt]
> > %
> > \text{Sum} =& -i\hbar \left[ \fpar{}{x_i}A_j - \fpar{}{x_j}A_i \right]
> > = -i\hbar \left[ \vec{\nabla}\times \vec{A} \right]_k
> > \end{align*}
> >
> > it almost works.  here's what i'm getting:
> >
> >
> >       a  =  b + f
> >       d  =  e + f
> > --------------------
> >      a+d = b + e +f
> >
> > the hrule goes to the left margin.  i've tried playing around with
> > parboxes to no avail.
> >
> >
> > anyone know how to do this?
> >
> > pete