Math & Science ⇒ Underbrace with Subarray in Text

[tho_mi]

Hey,

I have several formulas with underbraces and text where i need line breaks. In order to split the text I use subarrays, but it gives me a lot of errors (although I get a PDF file with the formatting I want).

Code: Select all

\documentclass[mathserif,10pt]{beamer}
\usepackage{lmodern}
\usepackage{amsmath,amssymb}

\begin{document}

\begin{frame}[c]{}
  $
    \underbrace{a}_\text{\begin{subarray}{c}\text{Gross}\end{subarray}}
  $
\end{frame}

\end{document}

Does anyone know why Latex misses several $s?

Thanks in advance

[hugovdberg]

Yes I do know The problem is that subarray as the name says is meant as part of another math environment. However, your subscript is entirely in a \text macro, and so effectively outside math mode. The solution is pretty simple, remove the \text command, and all is fine (output attached as PDF):

Code: Select all

\documentclass[mathserif,10pt]{beamer}
\usepackage{lmodern}
\usepackage{amsmath,amssymb}

\begin{document}

\begin{frame}[c]{}
  $
    \underbrace{a}_{\begin{subarray}{c}\text{Gross}\end{subarray}}
  $
\end{frame}

\end{document}

[tho_mi]

Thanks

Well, now I have another problem/question (see below code).

Code: Select all

\documentclass[mathserif,10pt]{beamer}
\usepackage{lmodern}
\usepackage{amsmath,amssymb}

\begin{document}

\begin{frame}[c]{}
  %\begin{center}
  $
  \underbrace{GDP}_{\begin{subarray}{c}\text{Gross}\\\text{domestic}\\\text{product}\end{subarray}}
  \quad = \quad \underbrace{C + I + G}_{\begin{subarray}{c}\text{Gross}\\\text{national}\\\text{expenditure}\\GNE\end{subarray}}
  \quad + \quad \underbrace{\left(\underbrace{EX}_{\begin{subarray}{c}\text{All exports,}\\\text{final \& intermediate}\end{subarray}} - \underbrace{IM}_\text{\begin{subarray}{c}\text{All exports,}\\\text{final \& intermediate}\end{subarray}}\right)}_{\begin{subarray}{c}\text{Trade balance}\\TB\end{subarray}}
  $
  %\end{center}
\end{frame}

\end{document}

It gives me eight errors, always "missing $ inserted" and I have no idea why.

[hugovdberg]

First of all, use some new lines and indentation in nested commands such as these. That makes it a lot easier to debug them, both for yourself and when requesting support. Second, an inline MWE helps in getting support too, since someone else doesn't have to download your file first, I often already spot the problem in the browser, and prefer not to switch to a texteditor first

Having said that, I indented your code for you, I think you'll spot the problem yourself soon enough Hint: it's the same problem as before, please take a look at what I posted yesterday for an explanation and the solution.

Code: Select all

\documentclass[mathserif,10pt]{beamer}
\usepackage{lmodern}
\usepackage{amsmath,amssymb}

\begin{document}

%>--- Slide --------------------------------------
\begin{frame}[c]{}
	%\begin{center}
	$
	\underbrace{GDP}_{
		\begin{subarray}{c}
			\text{Gross}\\
			\text{domestic}\\
			\text{product}
		\end{subarray}}
	\quad = \quad \underbrace{C + I + G}_{
		\begin{subarray}{c}
			\text{Gross}\\
			\text{national}\\
			\text{expenditure}\\
			GNE
		\end{subarray}}
	\quad + \quad \underbrace{\left(
		\underbrace{EX}_{
			\begin{subarray}{c}
				\text{All exports,}\\
				\text{final \& intermediate}
			\end{subarray}}
		 - \underbrace{IM}_\text{
		 	\begin{subarray}{c}
		 		\text{All exports,}\\
		 		\text{final \& intermediate}
		 	\end{subarray}
		 	}
		\right)}_{
		 	\begin{subarray}{c}
		 		\text{Trade balance}\\
		 		TB
		 	\end{subarray}}
	$
	%\end{center}
\end{frame}

\end{document}

[tho_mi]

Usually I use indendations, but in this case I was a bit lazy

Aaaah, thanks. I thought that there are not "\text" left... -.-"