# Braces alignment in Tikz

I have the following code to create a timeline with events labelled. In the second figure, between the events $(\tau_1+\frac{x_1}{K_1},x_2)$, I would like to place a curly bracket below, saying $\pi_1=...$ and below $(\tau_2,\tau)$ I would love to place another curly bracket with a different labelling.

In my code, when I run, the bracket turns out to be ugly and not the usual stylish one. I have tried changing the amplitude but to no avail.

\usepackage{tikz}
\usetikzlibrary{snakes, arrows, automata, positioning, calc, decorations.pathreplacing}

\begin{figure}
\begin{tikzpicture}
\draw (0.5,0) -- (7,0);
\draw[xshift=0.45 cm, thick] (5pt,5pt) -- (5pt,-5pt)node[above=0.3cm,fill=white] {0};
\draw[xshift=1 cm, thick] (5pt,5pt) -- (5pt,-5pt) node[above=0.3cm,fill=white] {$\tau_1$};
\draw[xshift=2.5 cm, thick] (5pt,5pt) -- (5pt,-5pt) node[above=0.3cm,fill=white] {$\tau_2$};
\draw[xshift=3.5 cm, thick] (5pt,5pt) -- (5pt,-5pt) node[above=0.3cm,fill=white] {$\tau_1+\frac{x_1}{K_1}$};
\draw[xshift=6.5cm, thick] (5pt,5pt) -- (5pt,-5pt) node[above=0.3cm,fill=white] {$\tau$};
\end{tikzpicture}
\begin{tikzpicture}
\draw (0.5,0) -- (7,0);
\draw[xshift=0.45 cm, thick] (5pt,5pt) -- (5pt,-5pt)     node[above=0.3cm,fill=white] {0};
\draw[xshift=1 cm, thick] (5pt,5pt) -- (5pt,-5pt) node[above=0.3cm,fill=white] {$\tau_1$};
\draw[xshift=2.5 cm, thick] (5pt,5pt) -- (5pt,-5pt) node[above=0.3cm,fill=white] {$\tau_1+\frac{x_1}{K_1}$};

\draw[xshift=3.5 cm, thick] (5pt,5pt) -- (5pt,-5pt) node[above=0.3cm,fill=white] {$\tau_2$};

\draw [decorate,decoration={brace,amplitude=-10pt},xshift=0pt,yshift=-1pt, mirror]
(3.5,-0.5) -- (6.5,-0.5) node [black,midway, yshift=-0.6cm] {\footnotesize $\pi_i=1+q(\pi_1-1)$};

\draw[xshift=6.5 cm, thick] (5pt,5pt) -- (5pt,-5pt) node[above=0.3cm,fill=white] {$\tau$};
\end{tikzpicture}

\end{figure}


• there is this raise key ;) – percusse Feb 1 '16 at 11:56

mirror is an option for decoration={}. Also, do not use a negative amplitude:

\documentclass[tikz]{standalone}
\usetikzlibrary{decorations.pathreplacing,calc}

\begin{document}
\begin{tikzpicture}
\coordinate (A) at (0.45,0);
\coordinate (B) at (1,0);
\coordinate (C) at (2.5,0);
\coordinate (D) at (3.5,0);
\coordinate (E) at (6.5,0);

\draw (0,0) -- (7,0);

\draw[thick] ($(A)+(0,5pt)$) node[above] {$0$} -- ($(A)-(0,5pt)$);
\draw[thick] ($(B)+(0,5pt)$) node[above] {$\tau_1$} -- ($(B)-(0,5pt)$);
\draw[thick] ($(C)+(0,5pt)$) node[above] {$\tau_1+\frac{x_1}{K_1}$} -- ($(C)-(0,5pt)$);
\draw[thick] ($(D)+(0,5pt)$) node[above] {$\tau_2$} -- ($(D)-(0,5pt)$);
\draw[thick] ($(E)+(0,5pt)$) node[above] {$\tau$} -- ($(E)-(0,5pt)$);

\draw[decorate,decoration={brace,amplitude=5pt,mirror,raise=3mm}] (C) -- (D) node [black,midway,yshift=-7mm] {\footnotesize $\pi_i=1+q(\pi_1-1)$};
\end{tikzpicture}
\end{document}


See, if you liked the following:

\documentclass[border=3mm,
tikz,
preview
]{standalone}
\usetikzlibrary{decorations.pathreplacing
}

\begin{document}
\begin{tikzpicture}
\draw (0,0) -- (7,0);
\foreach \i/\j in {0.45/0,1/$\tau_1$,2.5/$\tau_2$,3.5/$\tau_1+\frac{x_1}{K_1}$,6.5/$\tau$}
\draw (\i,-5pt) -- + (0,10pt) node[above] {\j};
\end{tikzpicture}

\begin{tikzpicture}[
decoration={brace,amplitude=10pt,raise=8pt,mirror}
]
\draw (0,0) -- (7,0);
\foreach \i/\j in {0.45/0,1/$\tau_1$,2.5/$\tau_2$,3.5/$\tau_1+\frac{x_1}{K_1}$,6.5/$\tau$}
\draw (\i,-5pt) -- + (0,10pt) node[above] {\j};

\draw[decorate]
(3.5,0) -- node[below=15pt] {\footnotesize $\pi_i=1+q(\pi_1-1)$} ++ (3,0) ;
\end{tikzpicture}
\end{document}


As you can see, I slightly reorganize your code, and make it quit shorter ...