Given an equation, say Bayes' rule,
$P(X \mid O) \propto P(X)P(O \mid X)$
how do I label the different parts of the equation using curly braces?
[Tex/LaTex] Using braces to label parts of an equation
bracesequations
Related Solutions
No need of \phantom and split; the best approach in this case is with the multlined environment provided by mathtools.
\documentclass{article}
\usepackage{mathtools}
\newcommand{\D}{\mathbf{D}}
\newcommand{\K}{\mathbf{K}}
\begin{document}
\begin{equation}\label{eq:split}
\begin{gathered}
c(x, y, t) =
\begin{multlined}[t]
\frac{M/Y}{b\sqrt{4\pi(\D_x^T+\K_x)t}}
\exp\biggl[-\frac{(x-Ut-x_0)^2}{4(\D_x^T+\K_x)t}\biggr]\\
\frac{b}{\sqrt{4\pi(\D_y^T+\K_y)t}}
\biggl\{
\sum_{j=-\infty}^{\infty}\exp\biggl[-\frac{(y-y_0+2jb)^2}{4(\D_y^T+\K_y}\biggr]\\
{}+\exp\biggl[-\frac{(y+y_0+2jb)^2}{4(\D_y^T+\K_y)}\biggr]
\biggr\}
\end{multlined}
\end{gathered}
\end{equation}
\end{document}
Notice that I've removed all \left and \right before the inner parentheses: they aren't needed and add spacing.
By choosing \biggl[ and \biggr] instead of \left[ and \right] we get uniform height of the brackets and we can use also the same size for the braces. In general, when a summation has limits above and below, \biggl and \biggr are to be preferred to \left and \right that produce too large symbols.
The wrapping gathered environment is used for getting the equation number centered with respect to the whole formula.
A refinement can be obtained by seeing that the two square root symbols are different though they contain similar formulas. If the second one is typed as
\sqrt{\smash[b]{4\pi(\D_y^T+\K_y)t}\vphantom{_x}}
the result will be
Here is a primitive meta-decoration, but it is not as general as the standard brace such as raise,mirror etc. won't work. However, the brace amplitude and other local brace options are passed and would be available as I tried to show below. The new raise amount is controlled with meta-amplitude key.
\documentclass[tikz]{standalone}
\usetikzlibrary{decorations.pathreplacing}
\pgfdeclaremetadecoration{raisedbrace}{initial}{%
\state{initial}[width=\pgfmetadecoratedpathlength]{%
\decoration{brace}%
\pgfsetdecorationsegmenttransformation{%
\pgftransformyshift{\pgfmetadecorationsegmentamplitude}%
}
\beforedecoration{
\pgfpathmoveto{\pgfpointmetadecoratedpathfirst}
\pgfpathlineto{\pgfpointadd{%
\pgfpointmetadecoratedpathfirst%
}{%
\pgfpointpolar{\pgfdecoratedangle+90}{\pgfmetadecorationsegmentamplitude}%
}%
}%
}%
\afterdecoration{%
\pgfpathlineto{\pgfpointmetadecoratedpathlast}%
\pgfusepath{stroke}
}
}
}
\begin{document}
\begin{tikzpicture}
\draw[style=help lines] (-1,-1) grid[step=1cm] (3,3);
\draw[decorate,decoration={raisedbrace,amplitude=2mm,meta-amplitude=4mm}] (0,1) -- (2,2);
\draw[decorate,decoration={raisedbrace,amplitude=4mm,meta-amplitude=1cm}] (0,-1) -- (2,-0.5);
\draw[decorate,decoration={raisedbrace,amplitude=1cm,meta-amplitude=5mm}] (2,3) -- (2,-0.5);
\end{tikzpicture}
\end{document}
Best Answer
I think you're after the
\underbraceand\overbracecommands, which you could use asWhich results in: