# Formula with text, good design?

I have the following text in my align environment, but it does not look good. So what should I change in order to get a better design/output?

\documentclass[a4paper,
12pt,
]{scrreprt}
\usepackage{amsmath}
\begin{document}
\begin{align}
R_ {t+1}^{simple}=\frac{\text{(asset price at t+1) $-$ (asset price at t)}}{\text{asset price at t}} \hspace*{0.5cm}r_{t+1}^{log}=ln \left( \frac{\text{asset price at t+1}} {\text{asset price at t}}\right) \hspace*{0.2cm}
\end{align}
\end{document}

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You should probably define a notation like $P_t$ and $P_{t+1}$ for prices respectively at $t$ and $t+1$, end your formula with a comma and add “where $P_t$ and $P_{t+1}$ respectively mean …” after the formula – Vincent Nivoliers Mar 26 '13 at 13:53

I would

1. format textual superscripts with \textrm
2. use \ln instead of just ln (assuming this is a logarithm)
3. use equation instead of align for a single equation
4. define a variable for the asset price to reduce repeating text.

That gives:

\documentclass[a4paper,
12pt,
]{scrreprt}
\usepackage{amsmath}
\parindent0pt
\begin{document}
Old version:
\begin{align}
R_ {t+1}^{simple}=\frac{\text{(asset price at t+1) $-$ (asset price at t)}}{\text{asset price at t}} \hspace*{0.5cm}r_{t+1}^{log}=ln \left( \frac{\text{asset price at t+1}} {\text{asset price at t}}\right) \hspace*{0.2cm}
\end{align}

New version:
$$R_{t+1}^{\textrm{simple}} = \frac{P_{t+1}-P_t}{P_t} \qquad r_{t+1}^{\textrm{log}} = \ln \left(\frac{P_{t+1}} {P_t}\right),$$
where  $P_t$ is the asset price at $t$.
\end{document}


and looks like this:

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I agree, this is a good recommendation. @mafp, what are you using to make the image? – daleif Mar 26 '13 at 14:32
@daleif I pulled a rectangle around that stuff in my PDF viewer, and saved it as a png. – mafp Mar 26 '13 at 14:34
thanks, I usually use dvipng, but it tends to cut stuff of at the edges. – daleif Mar 26 '13 at 14:39
@mafp and how can I get a space between the two formulas? So that the $r^log_{t+1}$ is a bit more to the right? – Stat Tistician Mar 26 '13 at 18:27
@StatTistician You can use one of the thin spaces, like \,. – mafp Mar 26 '13 at 19:05

You should be more careful with what is math and what is text. I would do something like this

R_ {t+1}^{\textup{simple}}=
\frac{\text{(asset price at $t+1$) $-$ (asset price at $t$)}}
{\text{asset price at $t$}}
\hspace*{0.5cm}
r_{t+1}^{\textup{log}}=
\operatorname{ln} \left(
\frac{\text{asset price at $t+1$}}
{\text{asset price at $t$}}
\right)


Now all the t should look alike. I don't see the point in the last hspace

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