I want to use this overly command
<2->\alert<2>
inside an equation environment to color some terms.
How can I do this?
[Tex/LaTex] Beamer color overlay in equation environment
beamerequationsoverlays
Related Solutions
Here is one option using alignat*
\documentclass[handout,13pt,compress,c]{beamer}
\usepackage{amsmath}
\usepackage{xcolor}
\usepackage{mathtools}
\usetheme{PaloAlto}
\begin{document}
\begin{frame}
\frametitle{Physical equations}
\framesubtitle{The equations that we are solving by Enzo during the
simulation}
\begin{alertblock}{Eulerian equations of ideal magnetohydrodynamics (MHD)
including gravity, in comoving coordinate}
\[ \frac{\partial \rho }{\partial t} + \frac{1}{a}\nabla .(\rho \vec{v}) =
0
\]
\[ \frac{\partial \rho \vec{v}}{\partial t} + \dfrac{1}{a}\nabla
.\left(\rho \vec{v}\vec{v} + \vec{I}p^* - \frac{\vec{B}\vec{B}}{a}\right) =
-\frac{\dot{a}}{a}\rho \vec{v} - \frac{1}{a}\rho \nabla \phi
\]
\begin{alignat*}{2}
\frac {\partial E} {\partial t} + \frac {1}{a} \nabla . \left[ (E+p^*) -
\frac{1}{a}\vec{B}(\vec{B}.\vec{v})\right] &= &&-
\frac{\dot{a}}{a}\left(2E - \frac{B^2}{2a}\right) \\
& && - \frac{\rho}{a}\vec{v}.\nabla \phi
- \Lambda + \Gamma\\
& && + \dfrac{1}{a^2}\nabla . \vec{F}_{cond},
\end{alignat*}
\end{alertblock}
\end{frame}
\end{document}
Also, you don't need \dfrac in display math and you should use \[\] over double dollars.
Why is \[ ... \] preferable to $$ ... $$?
By naming, do mean numbering and referencing a label name later on?
\begin{align}
\dfrac{\partial \rho }{\partial t} + \dfrac{1}{a}\nabla .(\rho \vec{v}) &=
0\label{eqname}\\
\dfrac{\partial \rho \vec{v}}{\partial t} + \dfrac{1}{a}\nabla
.\left(\rho \vec{v}\vec{v} + \vec{I}p^* - \dfrac{\vec{B}\vec{B}}{a}\right)
&=
-\dfrac{\dot{a}}{a}\rho \vec{v} - \dfrac{1}{a}\rho \nabla
\phi\label{eq2name}
\end{align}
\vspace*{-.6cm} \begin{alignat}{2}
\dfrac {\partial E} {\partial t} + \dfrac {1}{a} \nabla . \left[ (E+p^*) -
\dfrac{1}{a}\vec{B}(\vec{B}.\vec{v})\right] &= &&-
\dfrac{\dot{a}}{a}\left(2E - \dfrac{B^2}{2a}\right) \notag\\
& && - \frac{\rho}{a}\vec{v}.\nabla \phi
- \Lambda + \Gamma\notag\\
& && + \dfrac{1}{a^2}\nabla . \vec{F}_{cond},\label{eq3name}
\end{alignat}
To change the numbers to names, add \tag{name}.
\begin{align}
\dfrac{\partial \rho }{\partial t} + \dfrac{1}{a}\nabla .(\rho \vec{v}) &=
0\tag{Mass Conservation}\\
\dfrac{\partial \rho \vec{v}}{\partial t} + \dfrac{1}{a}\nabla
.\left(\rho \vec{v}\vec{v} + \vec{I}p^* - \dfrac{\vec{B}\vec{B}}{a}\right)
&=
-\dfrac{\dot{a}}{a}\rho \vec{v} - \dfrac{1}{a}\rho \nabla
\phi\tag{Momentum Conservation}
\end{align}
\vspace*{-.6cm}
\begin{alignat}{2}
\dfrac {\partial E} {\partial t} + \dfrac {1}{a} \nabla . \left[ (E+p^*) -
\dfrac{1}{a}\vec{B}(\vec{B}.\vec{v})\right] &= &&-
\dfrac{\dot{a}}{a}\left(2E - \dfrac{B^2}{2a}\right) \notag\\
& && - \frac{\rho}{a}\vec{v}.\nabla \phi
- \Lambda + \Gamma\notag\\
& && + \dfrac{1}{a^2}\nabla . \vec{F}_{cond},
\tag{Total Fluid Energy}
\end{alignat}
There is no \normaltext command, it is possible to change the series of the font with the \mdseries command, which sets it to medium, or with the \normalfont command, which sets the font series, shape and familiy to the default value.
So what you need is something like:
\documentclass{beamer}
\usecolortheme{seagull}
\setbeamerfont{alerted text}{series=\mdseries}
\begin{document}
\alert{test}
\end{document}
There is also a \textnormal{} macro, which is the bracketed version of \normalfont (as \textmd{} is the bracketed version of mdseries).
Best Answer
You really should provide a more complete example. I'm guessing that you may be after something like the example below, but if my guess is wrong I'll delete this answer.