# How to draw a graph of a specific form in LaTeX

How can I draw a graph like this in LaTeX using pgfplot package?

• Hi, welcome to TeX.SX! Have you tried anything? If so, can you show us the code you have so far? – Torbjørn T. Jun 13 '16 at 8:26
• So far, I have been trying the usual one \begin{tikzpicture} \begin{axis}[ axis lines = left, xlabel = $Tails(x)$, ylabel = $Heads(y)$, ] \addplot [ domain=0:15, samples=15, ] {- x + 10}; \addlegendentry{$x+y=n$} Thank you – Ragnar Jun 13 '16 at 8:52
• I think you might find useful How to make a figure with moving arrows? – Claudio Fiandrino Jun 13 '16 at 8:52
• God! I can not even right the code!! – Ragnar Jun 13 '16 at 8:54
• Yes, I think that can solve my problem. @ClaudioFiandrino – Ragnar Jun 13 '16 at 8:56

## 2 Answers

I have edited a little bit on the code given by @Claudio. and I came up with this solution.

\documentclass[10pt]{article}
\usepackage{pgfplots}
\begin{document}
\begin{tikzpicture}

\draw[->, thick](0,0)--node[below]{$Tails(x)$}(5,0) ;
\draw[->, thick](0,0)--node[left]{$Heads(y)$}(0,5);
\draw[- ] (4,0)node[below]{$(n,0)$}--(0,4) node[right] {$(0,n)$};

\node[right] at (3.6,0.4) {$(n-1,1)$};
\node[right] at (0.4,3.6) {$(1,n-1)$};
\node[right] at (0.8,3.2) {$(2,n-2)$};
\node[right] at (3,3) {$\mathbf{x+y=n}$};

\fill (0,4) circle (1.5pt);
\fill (4,0) circle (1.5pt);
\fill (3.6,0.4) circle (1.5pt);
\fill (0.4,3.6) circle (1.5pt);
\fill (0.8,3.2) circle (1.5pt);

\end{tikzpicture}
\end{document}

• \usepackage{amsmath} and then $\text{Tails}(x)$, $\text{Heads}(y)$. – Torbjørn T. Jun 13 '16 at 21:01
• sorry for not mentioning \usepackage{amsmath} but the other two are done in a different way, as repositioned nodes. @TorbjørnT. – Ragnar Jun 13 '16 at 21:11
• My main point was that you don't want to write Tails and Heads in math mode, they are words, not a string of variables. I only mentioned amsmath because it defines \text. – Torbjørn T. Jun 13 '16 at 21:14
• Alright, but '\mathbf' is also from 'amsmath ' package, if I am not wrong. – Ragnar Jun 13 '16 at 21:18
• No, you don't need amsmath to use \mathbf (which your example proves, it works without amsmath). Don't think amsmath defines any font styles at all actually, but for \mathbb for example you need amsfonts. – Torbjørn T. Jun 13 '16 at 21:26

Your comment is almost a solution. You might want to use axis lines=middle to match the sketch from your question.

\documentclass{article}
\usepackage{pgfplots}
\begin{document}
\begin{tikzpicture}
\begin{axis}[axis lines=middle,
xlabel=$\mathrm{Tails}(x)$,
ylabel=$\mathrm{Heads}(y)$,
domain=0:15,no marks]
\addplot {-x + 10};
\addlegendentry{$x+y=n$}
\end{axis}
\end{tikzpicture}
\end{document}