alignequations
I am trying to align two equations, however they are not aligning at the equals sign but at the comma at the end of the equation. How can I change this?
\begin{align}
A_{ij}^y=
\begin{cases}
1, & \text{if the link between $x_{i,j}$ and $y_{i,j}$ is included},\\
0, & \text{otherwise},
\end{cases} \\
R_{ij} = r_{ij},
\end{align}
Thanks for your help
Please always post complete documents, not just fragments.
You can use \phantom
\documentclass{article}
\usepackage{amsmath}
\begin{document}
\begin{align}
\begin{split}
\left| \Psi \left( t \right) \right\rangle _{I}^{3}&=-\frac{1}{{{\hbar}^{2}}}\int_{0}^{t}{\hat{H}_{1}^{I}\left( t' \right)\,}\left( \int_{0}^{t}{\hat{H}_{1}^{I}\left( t'' \right)dt''} \right)dt' \notag \\
& =-\frac{1}{\hbar }\int_{0}^{t}{\hat{H}_{1}^{I}\left( t' \right)\,}\left( -\frac{g}{\Delta }\left( -{{{\hat{A}}}_{+}}\left( {{e}^{-i\Delta t'}}-1 \right)+{{{\hat{A}}}_{-}}\left( {{e}^{i\Delta t'}}-1 \right) \right) \right)dt' \notag \\
& =\frac{1}{\hbar }\int_{0}^{t}{\hbar g\left( {{{\hat{A}}}_{+}}{{e}^{-i\Delta t'}}+{{{\hat{A}}}_{-}}{{e}^{i\Delta t'}} \right)\,}\left( -\frac{g}{\Delta }\left( -{{{\hat{A}}}_{+}}\left( {{e}^{-i\Delta t'}}-1 \right)+{{{\hat{A}}}_{-}}\left( {{e}^{i\Delta t'}}-1 \right) \right) \right)dt' \notag \\
&=-\frac{{{g}^{2}}}{\Delta }\Bigg[ -\frac{1}{2i\Delta }{{e}^{-2i\Delta t'}}{{{\hat{A}}}_{+}}{{{\hat{A}}}_{+}}+\frac{1}{i\Delta }{{e}^{-i\Delta t'}}{{{\hat{A}}}_{+}}{{{\hat{A}}}_{+}}-{{{\hat{A}}}_{+}}{{{\hat{A}}}_{-}}-\frac{1}{i\Delta }{{e}^{-i\Delta t'}}{{{\hat{A}}}_{+}}{{{\hat{A}}}_{-}} \\
&\phantom{{}=-\frac{{{g}^{2}}}{\Delta }\Bigg[}+{{{\hat{A}}}_{-}}{{{\hat{A}}}_{+}}-\frac{1}{i\Delta }{{e}^{i\Delta t'}}{{{\hat{A}}}_{-}}{{{\hat{A}}}_{+}}-\frac{1}{2i\Delta }{{e}^{2i\Delta t'}}{{{\hat{A}}}_{-}}{{{\hat{A}}}_{+}}+\frac{1}{i\Delta }{{e}^{i\Delta t'}}{{{\hat{A}}}_{-}}{{{\hat{A}}}_{+}} \Bigg]_{0}^{t} \notag
\end{split}
\end{align}
\end{document}
(I'm assuming this is cut down from some larger example, as there is no need to have an alignment just consisting of a split)
I only considered implementing a global alignment as egreg hinted in comments that it was a bad idea. Alignment is supposed to highlight the corresponding parts of a display and that meaning is destroyed if you align everything. But...
\documentclass{article}
\usepackage[fleqn]{amsmath}
\usepackage{etoolbox}
\setlength\mathindent{3cm}
\makeatletter
\def\align@preamble{%
&\hfil
\strut@
\setboxz@h{\@lign$\m@th\displaystyle{##}$}%
\ifmeasuring@\savefieldlength@\fi
\llap{\set@field}%
\tabskip\z@skip
&\setboxz@h{\@lign$\m@th\displaystyle{{}##}$}%
\ifmeasuring@\savefieldlength@\fi
\rlap{\set@field}
\hfil
\tabskip\alignsep@
}
\def\a{One two three four five six seven. }
\def\b{\a\a\a Red yellow blue green. \a\a\a\a}
\begin{document}
\b\b\a
\begin{align}
1+2+3+4 &=4\\
x+y &=z
\end{align}
\b\b\b
\a\a\b
\a
\begin{align}
1&=a+y+b+w+x+n+m+s+d+e\\
2&=4
\end{align}
\b
\begin{align}
1&=0\\
2&=9
\end{align}
\end{document}
the macros here are not particularly general or robust but show a basic idea of using a flush left but very indented setting along with hiding the width of the first column.
Best Answer
You have to place the alignment marks
&at the equals sign:Also, I have used the
cases*environment from themathtoolspackage to typeset the cases, as that typesets the second column in text mode.