On June 20, 2003 09:18 am, Chris Carlen wrote:
> Hi:
>
> I'm going to give this one last shot, before I give up on the math
> editor for this particular problem, and write in plain LaTeX.
>
> I want to show an four line equation, in which each equation has
> fractional expressions. Also, I want a left brace delimiter around the
> whole thing.
>
> The multiline equation env. won't help me here, since it doesn't allow
> the delimiter.
>
> The array env. works, but causes the fractional expressions to be set in
> a smaller font than the non-fractional stuff. This can be fixed by the
> use of \displaystyle, which prevents the shrinking of the fractions.
>
> The only remaining problem is that the fractional expressions from the
> different lines of the set of four equations are too close to each
> other, so it looks ugly in the printout.
>
> What I have so far is this, which was done entirely in mathed:
>
> \[\left\{ \begin{array}{ccc} a_{\omega} & = & {\displaystyle
> \frac{R_{L}}{K_{V}(R_{L}+R_{m})}}\\ b_{\omega} & = & {\displaystyle
> \frac{i_{L}R_{L}R_{m}}{K_{V}(R_{L}+R_{m})}}\\ a_{i} & = & {\displaystyle
> \frac{1}{R_{m}+R_{L}}}\\ b_{i} & = & {\displaystyle
> \frac{i_{L}R_{L}}{R_{m}+R_{L}}}\end{array}\right.\]
>
> What can I do to this to make the lines of the array separated a little
> bit vertically? That is all I need to fix the last remaining problem.
>
> Also, can such a fine-tuning be accomplished in the mathed, or can it
> only be done by editing the equation in LaTeX?
>
>
> Thanks for assistance.
>
>
> Good day!
Put a \vspace{0.25cm} (or whatever spacing you're happy with) at the end of
each of the first three lines in the array.
I've attached a LyX file with your equations typeset in various ways,
including the \cases AMS math environment suggested by Dekel Tsur.
Hope this helps,
Johnathan
--
Johnathan K. Burchill, Ph.D. candidate
Department of Physics and Astronomy
University of Calgary
2500 University Drive N.W.
Calgary, AB T2N 1N4
Canada
(403) 217-4286
[EMAIL PROTECTED]
#LyX 1.3 created this file. For more info see http://www.lyx.org/
\lyxformat 221
\textclass article
\language english
\inputencoding auto
\fontscheme default
\graphics default
\paperfontsize default
\spacing single
\papersize Default
\paperpackage a4
\use_geometry 0
\use_amsmath 1
\use_natbib 0
\use_numerical_citations 0
\paperorientation portrait
\secnumdepth 3
\tocdepth 3
\paragraph_separation indent
\defskip medskip
\quotes_language english
\quotes_times 2
\papercolumns 1
\papersides 1
\paperpagestyle default
\layout Standard
>From Mathed:
\layout Standard
\begin_inset Formula \[
\left\{\begin{array}{ccc}
a_{\omega} & = & {\displaystyle \frac{R_{L}}{K_{V}(R_{L}+R_{m})}}\\
b_{\omega} & = & {\displaystyle \frac{i_{L}R_{L}R_{m}}{K_{V}(R_{L}+R_{m})}}\\
a_{i} & = & {\displaystyle \frac{1}{R_{m}+R_{L}}}\\
b_{i} & = & {\displaystyle \frac{i_{L}R_{L}}{R_{m}+R_{L}}}\end{array}\right.\]
\end_inset
\layout Standard
>From ERT (I cut and paste your latex code to verify my mathed interpretation
of it):
\layout Standard
\begin_inset ERT
status Open
\layout Standard
\backslash
[
\backslash
left
\backslash
{
\backslash
begin{array}{ccc} a_{
\backslash
omega} & = & {
\backslash
displaystyle
\backslash
frac{R_{L}}{K_{V}(R_{L}+R_{m})}}
\backslash
\backslash
b_{
\backslash
omega} & = & {
\backslash
displaystyle
\backslash
frac{i_{L}R_{L}R_{m}}{K_{V}(R_{L}+R_{m})}}
\backslash
\backslash
a_{i} & = & {
\backslash
displaystyle
\backslash
frac{1}{R_{m}+R_{L}}}
\backslash
\backslash
b_{i} & = & {
\backslash
displaystyle
\backslash
frac{i_{L}R_{L}}{R_{m}+R_{L}}}
\backslash
end{array}
\backslash
right.
\backslash
]
\end_inset
\layout Standard
>From Mathed with
\backslash
vspace{0.25cm} at the end of the first three array lines:
\layout Standard
\begin_inset Formula \[
\left\{\begin{array}{ccc}
a_{\omega} & = & {\displaystyle \frac{R_{L}}{K_{V}(R_{L}+R_{m})}}\vspace{.25cm}\\
b_{\omega} & = & {\displaystyle \frac{i_{L}R_{L}R_{m}}{K_{V}(R_{L}+R_{m})}}\vspace{.25cm}\\
a_{i} & = & {\displaystyle \frac{1}{R_{m}+R_{L}}}\vspace{.25cm}\\
b_{i} & = & {\displaystyle \frac{i_{L}R_{L}}{R_{m}+R_{L}}}\end{array}\right.\]
\end_inset
\layout Standard
Using AMS Math, with
\backslash
cases (no
\backslash
displaystyle):
\begin_inset Formula \[
\begin{cases}
a_{\omega} & =\frac{R_{L}}{K_{V}(R_{L}+R_{m})}\\
b_{\omega} & =\frac{i_{L}R_{L}R_{m}}{K_{V}(R_{L}+R_{m})}\\
a_{i} & =\frac{1}{R_{m}+R_{L}}\\
b_{i} & =\frac{i_{L}R_{L}}{R_{m}+R_{L}}\end{cases}\]
\end_inset
\the_end
