Thread: diagram

How do I draw the diagram in latex? And then in the center of my page?

Does anyone know?!!!

The simplest way is to use an array.

Code:

\begin{array}{cccccc}
\tilde e: & N_1+N_2 & \overset{\lambda}{\longrightarrow} & \tilde L & \overset{\rho}\twoheadrightarrow & Q\\
&\llap{$\sigma_i$}\downarrow &&\llap{$\tau_i$}\downarrow &&\llap{$\gamma_i$}\downarrow\\
e_i: & N_i & \overset{\chi_i}{\longrightarrow} & L_i & \overset{\pi_i}{\longrightarrow} & Q_i
\end{array}

gives



PFG/TikZ provides a better quality.

Code:

\usetikzlibrary{positioning,arrows}

\begin{tikzpicture}[auto,>=stealth']
\node (N1+N2) {$\llap{$\tilde e:{}$}N_1+N_2$};
\node[right=of N1+N2] (L) {$\tilde L$};
\node[right=of L] (Q) {$Q$};
\node[below=of N1+N2] (Ni) {$\llap{$e_i:{}$}N_i$};
\node[below=of L] (Li) {$L_i$};
\node[below=of Q] (Qi) {$Q_i$};
\draw[->] (N1+N2) -- node[swap] {$\sigma_i$} (Ni);
\draw[->] (L) -- node[swap] {$\tau_i$} (Li);
\draw[->] (Q) -- node[swap] {$\gamma_i$} (Qi);
\draw[->] (N1+N2) -- node {$\lambda$} (L);
\draw[->>] (L) -- node {$\rho$} (Q);
\draw[->] (Ni) -- node {$\tau_i$} (Li);
\draw[->>] (Li) -- node {$\pi_i$} (Qi);
\path[use as bounding box] (-1.5,0) rectangle (0,0);
\end{tikzpicture}

gives



See also this thread for links.

To place something in the middle of the page, you can use the following.

Code:

\pagebreak

\leavevmode
\vfill
\[ ... \]
\vfill
\pagebreak

Alternatively, request a full-page float (option p).

Code:

\begin{figure}[p]
\[ ... \]
\end{figure}

Originally Posted by emakarov

The simplest way is to use an array.

Code:

\begin{array}{cccccc}
\tilde e: & N_1+N_2 & \overset{\lambda}{\longrightarrow} & \tilde L & \overset{\rho}\twoheadrightarrow & Q\\
&\llap{$\sigma_i$}\downarrow &&\llap{$\tau_i$}\downarrow &&\llap{$\gamma_i$}\downarrow\\
e_i: & N_i & \overset{\chi_i}{\longrightarrow} & L_i & \overset{\pi_i}{\longrightarrow} & Q_i
\end{array}

gives



PFG/TikZ provides a better quality.

Code:

\usetikzlibrary{positioning,arrows}

\begin{tikzpicture}[auto,>=stealth']
\node (N1+N2) {$\llap{$\tilde e:{}$}N_1+N_2$};
\node[right=of N1+N2] (L) {$\tilde L$};
\node[right=of L] (Q) {$Q$};
\node[below=of N1+N2] (Ni) {$\llap{$e_i:{}$}N_i$};
\node[below=of L] (Li) {$L_i$};
\node[below=of Q] (Qi) {$Q_i$};
\draw[->] (N1+N2) -- node[swap] {$\sigma_i$} (Ni);
\draw[->] (L) -- node[swap] {$\tau_i$} (Li);
\draw[->] (Q) -- node[swap] {$\gamma_i$} (Qi);
\draw[->] (N1+N2) -- node {$\lambda$} (L);
\draw[->>] (L) -- node {$\rho$} (Q);
\draw[->] (Ni) -- node {$\tau_i$} (Li);
\draw[->>] (Li) -- node {$\pi_i$} (Qi);
\path[use as bounding box] (-1.5,0) rectangle (0,0);
\end{tikzpicture}

gives



See also this thread for links.

thank you very much...

but i'm wrote it in latex, then give error. said undefine usetikzlibrary, please help me

You can download TikZ from SourceForge.net. The manual (PDF) describes how to install it. The easiest way to install it manually is described in section 8.3.1, where you unpack the archive into texmf/tex/generic/pgf or texmf/tex/generic/pgf-2.10, where texmf is the root of a directory subtree where TeX stores its files. Of course, you need to say \usepackage{tikz} in the preamble of the LaTeX file; maybe your system will prompt you to download and install TikZ automatically when it encounters it. Then you also say \usetikzlibrary{positioning,arrows} in the preamble.