# I'm looking for a help for drawing this diagrams

I'm looking for a help for drawing this diagrams:

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Hi Angel, Welcome to TeX.SE! It's usually best to show what you have attempted first, and then specify in your question where you're struggling. Have a look in the manual, and search for 'commutative diagrams' on this site; that should get you started. Welcome! –  cmhughes Dec 23 '12 at 18:26
Welcome to TeX.SE!. On this website we prefer not to have questions of the "draw it for me" type. There are plenty of questions here which would help you draw these diagrams. If you are having problems with a specific issue in the graph, then this is the place, but you should provide a code showing your effort in trying to do it. I am voting to close this as too localised but I encourage you to improve this question and try again. –  Vivi Dec 23 '12 at 18:29
@Vivi (and others) please allow a bit of time before voting to close- we should welcome new members, and give them time to modify their question :) –  cmhughes Dec 23 '12 at 18:31
I can not draw second diagram,in fact I don't know how to draw Convex curve shape. –  Angel Dec 23 '12 at 18:43
“On this website we prefer not to have questions of the "draw it for me" type.” -- One would think so but people don't act like it. From what I have seen these questions always get answers, sometimes even really fast. I guess people like to show their TikZ skills... –  cgnieder Dec 23 '12 at 19:15

For the second figure, hope the following code helps. I cannot clearly see whether one of the curves is dashed. If that's not the case, remove [dashed] in the code.

\documentclass{standalone}
\usepackage{tikz}

\begin{document}
\begin{tikzpicture}
\coordinate (o) at (0,2);
\coordinate (a) at (-4,0);
\coordinate (b) at (4,0);
\draw (o) -- (a) -- (b) -- cycle;
\draw (0,0) arc (-53:53:1.25);
\draw[dashed] (0,2) arc (-53:53:-1.25);
\end{tikzpicture}

\end{document}


As for the first figure, you can easily achive with tikz-cd. This is one possibility.

\documentclass{standalone}
\usepackage{tikz}
\usepackage{tikz-cd}

\begin{document}

\begin{tikzcd}[column sep=small]
\mathcal{X}^*\arrow{rr}{\rho} &  & \mathcal{M}^*\\
& \frac{\mathcal{X}^*}{\mathcal{M}^\perp} \arrow[swap]{ur}{\tilde{\rho}}\arrow{ul}{Q}&
\end{tikzcd}

\end{document}


with the following result:

If you want to keep the fonts (almost) in your image,

\documentclass{standalone}
\usepackage{tikz}
\usepackage{tikz-cd}
\usepackage{amsmath}
\usepackage[mathscr]{euscript}

\begin{document}
\begin{tikzcd}[column sep=small]
\mathscr{X}^*\arrow{rr}{\rho} &  & \mathscr{M}^*\\
& \dfrac{\mathscr{X}^*}{\mathscr{M}^\perp} \arrow[swap]{ur}{\tilde{\rho}}\arrow{ul}{Q}&
\end{tikzcd}
\end{document}

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+1 a few folks recommend using \documentclass{standalone} for images- it has many advantages, including very-easily cropped pictures :) –  cmhughes Dec 23 '12 at 18:59
Thanks @cmhughes for the advice. –  c.p. Dec 23 '12 at 19:02
Thanks all and I apologize that my question was not raised properly.I can draw The First commutative diagram by xymatrix.‎\begin{displaymath}‎ ‎\xymatrix{‎ ‎\mathcal{X}‎^* \ar[rr]^{‎\rho‎}& &‎ ‎‎\mathcal{M}‎^* \\‎ ‎& ‎‎‎\frac{\mathcal{X}^*}{\mathcal{M}^‎\bot‎}‎\ar[ru]_{‎\tilde\rho‎} \ar[lu]^{Q} &}‎‎ ‎ ‎\end{displaymath}‎‎ –  Angel Dec 23 '12 at 22:13

For the first commutative diagram (still it need some fonts improvements):

\documentclass{standalone}

\usepackage{amssymb}
\usepackage{amsmath}
\usepackage{tikz}
\usetikzlibrary{matrix,arrows}

\begin{document}
\begin{tikzpicture}
\matrix (m) [matrix of math nodes, row sep=3em,
column sep=2.5em, text height=1.5ex, text depth=0.25ex] {
\mathcal{X}^* & & \mathcal{M}^* \\
& \dfrac{\mathcal{X}^*}{\mathcal{M}^{\perp}} & \\ };
\path[->] (m-1-1) edge node[above] {$\rho$} (m-1-3);
\path[->] (m-2-2) edge node[below] {$Q$} (m-1-1);
\path[->] (m-2-2) edge node[below] {$\tilde\rho$} (m-1-3);
\end{tikzpicture}
\end{document}


Result:

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