Math & Science ⇒ Horizontal Spacing within aligned Equations

[Cham]

I'm having a spacing problem with the following minimal working code. The first four items aren't horizontally spaced enough and I don't know why.

Code: Select all

\documentclass[12pt]{article}
\usepackage[T1]{fontenc}
\usepackage{mathtools}

\begin{document}
Test

  \begin{equation}
    \begin{gathered}
      \begin{aligned}
        \tilde{A} &= {\Omega}^{2} \, A,
        &\tilde{B} &= {\Omega}^{- 2} \, B, \\[12pt]
        \tilde{\Phi} &= {\Omega}^{w} \, \Phi,
        &\tilde{\Psi} &= {\Omega}^{w} \, \Psi,
      \end{aligned} \\[12pt]
      \tilde{A}_{\mu_1 \, \ldots \, \mu_q}^{\lambda_1 \, \ldots \, \lambda_p} = {\Omega}^{w} \, A_{\mu_1 \, \ldots \, \mu_q}^{\lambda_1 \, \ldots \, \lambda_p}.
    \end{gathered}
  \end{equation}
\end{document}

The aligned items should be spaced like in the align environment.

Any idea what is going on here?

[Johannes_B]

Would you be able to clarify what isn't aligned properly? Maybe by inserting comments directly inside the code or uploading a screen shot of the resulting PDF with little marks (done by Gimp or something similar).

Best regards
Johannes



PS: Remember to click on "Open in writeLaTeX" to see the same output that we see.

[Cham]

When you click on the "Open in writeLaTeX" button, you get a well compiled code. Except that the "A", "B", 'Phi" and "Psi" items are too close from each other (horizontally), compared to what we get in the usual align environment.

I think that the aligned environment should output the same horizontal spacing as the align environment.

Here's the output from the code above :

aligned.jpg (11.78 KiB) Viewed 40357 times

And here's the output from the code below (I'm not sure it's the proper way to do this, since I want a single equ. number for all the set of equations) :

align.jpg (11.82 KiB) Viewed 40357 times

Code: Select all

\documentclass[12pt]{article}
\usepackage[T1]{fontenc}
\usepackage{mathtools}

\begin{document}
Test
  \begin{align}
    \tilde{A} &= {\Omega}^{2} \, A,
    &\tilde{B} &= {\Omega}^{- 2} \, B, \nonumber \\[12pt]
    \tilde{\Phi} &= {\Omega}^{w} \, \Phi,
    &\tilde{\Psi} &= {\Omega}^{w} \, \Psi,
  \end{align}
  \begin{equation*}
    \tilde{A}_{\mu_1 \, \ldots \, \mu_q}^{\lambda_1 \, \ldots \, \lambda_p} = {\Omega}^{w} \, A_{\mu_1 \, \ldots \, \mu_q}^{\lambda_1 \, \ldots \, \lambda_p}.
  \end{equation*}
\end{document}

[cgnieder]

the "A", "B", 'Phi" and "Psi" items are too close from each other (horizontally), compared to what we get in the usual align environment.

Why don't you just use align then? (Probably because of the equation numbers?) You could also simply add horizontal spacing by inserting a \quad (inserts 1em of space), \qquad (inserts 2em of space) or \hspace{<dim>} in one of the lines.

I think that the aligned environment should output the same horizontal spacing as the align environment.

Well, the AMS which is maintaining amsmath seems to have a different opinion. The {aligned} environment is certainly not going to change since that would break lots of documents that rely upon its current behavior.

Regards

[Cham]

Well, I already tried the \qquad spacing trick, but the equal signs aren't properly aligned anymore (within a gather environment). And apparently, the align environment can't be used inside a gather environment, or can it ?

Edit: I'm an incredibly stupid idiot! Adding the \qquad spacing in the items, inside the aligned environment solves the issue!