equationshorizontal alignmentmultline
I want to achieve something like the following (for now achieved using Microsoft Paint):
That is, I want to group a number of multi-line equations within a single equation-type environment (i.e. they have the same number) and have each one aligned like in the "multline"-environment (first line left-aligned, last line right-aligned). Is this possible?
the multlined environment from mathtools is your friend. (it loads amsmath, so there's no need to do that).
two things to note about this example:
\mathindent is set to zero width within a group so it will disappear after the display ends.multlined (like multline) automatically sets the first line flush left and the last line flush right, you don't want the \shove... commands on those lines. in fact, the spacing will be compromised if you do wrap those lines in \shove... arguments.here's the code:
\documentclass{article}
\usepackage[fleqn]{mathtools}
\begin{document}
\noindent some text here
{\mathindent=0pt
\[
\setlength{\multlinegap}{0pt}
\left\{
\begin{multlined}
A_{PP}\sin\alpha_{P1} - A_{PS}\cos\alpha_{S1} +B_{PP} \sin\alpha_{P2} +B_{PS} \cos\alpha_{S2} = \\
\shoveright{=\sin\alpha_{P1},} \\
% 2-nd equation
\shoveleft{ A_{PP}\cos\alpha_{P1} +A_{PS} \sin\alpha_{S1} -B_{PP}\cos\alpha_{P2} + B_{PS} \sin\alpha_{S2} = } \\
\shoveright{ =\cos\alpha_{P1},} \\
% 3-rd equation
\shoveleft{ A_{PP}\gamma_{P1} \cos 2\alpha_{S1} +A_{PS} \gamma_{S1} \sin 2\alpha_{S1} +B_{PP} \gamma_{P2} \cos 2\alpha_{S2} -} \\
\shoveright{- B_{PS} \gamma_{S2} \sin 2\alpha_{S2} = \gamma_{P1} \cos 2\alpha_{S1},} \\
% 4-th equation
\shoveleft{ -A_{PP}n_1 \gamma_{S1} \sin 2\alpha_{P1} +A_{PS} \gamma_{S1} \cos 2\alpha_{S1} +B_{PP} n_2 \gamma_{S2} \sin 2\alpha_{P2} +} \\
+ B_{PS} \gamma_{S2} \cos 2\alpha_{S2} = n_1 \gamma_{S1} \sin 2\alpha_{P1}.
\end{multlined}
\right.
\] }
\end{document}
This doesn't really answer your question, but might solve your problem.
How about condensing the equation with constants? I threw in a macro \diff{}{} for differentials (which should be written with upright d's as it's an operator). Btw, there could be better choices for constants.
\documentclass[letterpaper,12pt]{article}
\usepackage{amsmath}
\newcommand{\diff}[2]{\frac{\mathrm{d}#1}{\mathrm{d}#2}}
\begin{document}
\begin{equation}
\diff{B}{t} = a_1(b_1e^{c_1t}+b_2e^{-c_2t}) - \left(a_2\frac{\ln{\frac{1}{2}}}{b_3} \right) \exp \left(\frac{\ln{\frac{1}{2}}}{b_3}\right)
\end{equation}
%
where the constants $a_i$, $b_i$, and $c_i$ are
%
\begin{align*}
a_1 &= -0.092409, && a_2 = 200, && \\
b_1 &= 22.2674, && b_2 = 77.7326, && b_3 = 26.8, \\
c_1 &= -0.092409, && c_2 = -0.0258637, &&
\end{align*}
%
such that
%
\begin{equation}
\diff{B}{t} \approx 2.057708e^{-0.092409 t}+7.18319e^{-0.0258637 t}
\end{equation}
\end{document}
Best Answer
The
\shoveleftand\shoverightcommands allow to flush left or right the equations of amultlineenvironment.Addendum
As pointed out by @barbara beeton, the position of the equation number is ambiguous. This can be solved by using the subsidiary environment
multlinedprovided bymathtoolsinside anequation(first proposed by @egreg). This approach also benefits from the improved spacing of theequationenvironment.