alignpositioningtwo-column
Is there a good/correct way of making an align environment with one line spanning multiple columns?
At the moment I'm using a hack like the following, but I feel that it's probably not the best way.
\documentclass{article}
\usepackage{amsmath}
\begin{document}
\begin{align}
L1C1 &= 1234 \,,& L1C2 &= abcd \,,\\
L2C1 &= 1234 \,,& L2C2 &= efgh \,,\\
L3 &= 1234567890abcdefghijklmnop \ . \hspace{-30cm}
\end{align}
\end{document}
I don't really get the question so I hope this is what you wanted. If you include a full document (such that we copy paste and see the problem on our systems) things are much more easier.
Here, you can change the default setting within a scope but your block style had a node distance which was resetting every time it is issued. I've made it 2mm such that we can see the difference easier.
\documentclass[tikz]{standalone}
\usetikzlibrary{arrows,shapes.geometric,positioning}
\begin{document}
\begin{tikzpicture}[decision/.style={diamond, draw, text width=4.5em, text badly centered, node distance=3.5cm, inner sep=0pt},
block/.style ={rectangle, draw, text width=6em, text centered, rounded corners, minimum height=4em, minimum height=2em},
cloud/.style ={draw, ellipse, minimum height=2em},
line/.style ={draw,-latex'},
node distance = 1cm,
auto]
\node [block] (1st) {1st};
\node [block, right= of 1st] (2nd1) {2nd1};
\begin{scope}[node distance=2mm and 10mm]%Here we change it for everything inside this scope
\node [block, above= of 2nd1] (2nd2) {2nd2};
\node [block, below= of 2nd1] (2nd3) {2nd3};
\node [block, right= of 2nd1] (3rd1) {3rd1};
\node [block, above= of 3rd1] (3rd2) {3rd2};
\node [block, above= of 3rd2] (3rd3) {3rd3};
\end{scope}
\node [block, below= of 3rd1] (3rd4) {3rd4};
\node [block, below= of 3rd4] (3rd5) {3rd5};
\path [line] (1st) -- (2nd1);
\path [line] (2nd1) -- (2nd2);
\path [line] (2nd1) -- (2nd3);
\path [line] (2nd2) -- (3rd3);
\path [line] (2nd1) -- (3rd1);
\path [line] (1st) -- (2nd1);
\end{tikzpicture}
\end{document}
You can use flalign*:
\nonumber.~ for spacing as manual spacing should normally be avoided in math.\documentclass[]{article}
\usepackage{showframe}
\usepackage{amsmath}
\begin{document}
\begin{flalign*}
\eta_7 &= \eta_2 f_0(\lambda) - \eta_1 g_0(\lambda)\nonumber&\eta_8 &= \eta_1 f_0(\lambda) + \eta_2 g_0(\lambda)\nonumber\\
\eta_9 &= \rlap{$pEL a - \displaystyle\frac{\sigma_c \lambda^2}{2}$}\\
\eta_{10} &= \rlap{$\sqrt{2} \left\{4 l^2 \left[\eta_2 f_0(\lambda) - \eta_1 g_0(\lambda)\right] - \left[\lambda^2 - a^2\right] \left[\eta_1 f_0(\lambda) + \eta_2 g_0(\lambda)\right]\right\}-4 l \lambda \eta_6$}
\end{flalign*}
\end{document}
Best Answer
this is also a hack, but it will give the desired result.
use
\rlapto "hide" the width of the overlong line. for the example given, i would do this for the last line:you might even want to put some extra space after that to get the desired separation; just look at the output to see what's needed.
most lines of math contain reasonable places where one can break without damage.
Update:
In a comment, @user2478 has suggested using
\mathrlap; requiresmathtools. (Yes, this is better than plain\rlap.)