The ternary library allows to draw ternary diagrams. A ternary diagram visualizes three-component systems such that the sum of them yields 100 percent. Ternary diagrams are triangular axes.
This example is a (crude) copy of an example of http://www.sv.vt.edu/classes/MSE2094_NoteBook/96ClassProj/experimental/ternary2.html and uses area style to change cycle list and the legend appearance.
The code is from the PGFPlots 1.10 manual: “5.12 Ternary Diagrams”.
\documentclass[border=10pt]{standalone}
\usepackage{pgfplots}
\pgfplotsset{width=7cm,compat=1.8}
\usepgfplotslibrary{ternary}
\begin{document}
\begin{tikzpicture}
\begin{ternaryaxis}[
title=Want--be--Stainless Steel,
xlabel=Weight Percent Chromium,
ylabel=Weight Percent Iron,
zlabel=Weight Percent Nickel,
label style=sloped,
area style,
]
\addplot3 table {
A B C
1 0 0
0.5 0.4 0.1
0.45 0.52 0.03
0.36 0.6 0.04
0.1 0.9 0
};
\addlegendentry{Cr}
\addplot3 table {
A B C
1 0 0
0.5 0.4 0.1
0.28 0.35 0.37
0.4 0 0.6
};
\addlegendentry{Cr+$\gamma$FeNi}
\addplot3 table {
0.4 0 0.6
0.28 0.35 0.37
0.25 0.6 0.15
0.1 0.9 0
0 1 0
0 0 1
};
\addlegendentry{$\gamma$FeNi}
\addplot3 table {
0.1 0.9 0
0.36 0.6 0.04
0.25 0.6 0.15
};
\addlegendentry{Cr+$\gamma$FeNi}
\addplot3 table {
0.5 0.4 0.1
0.45 0.52 0.03
0.36 0.6 0.04
0.25 0.6 0.15
0.28 0.35 0.37
};
\addlegendentry{$\sigma$+$\gamma$FeNi}
\node[inner sep=0.5pt,circle,draw,fill=white,
pin=-15:\footnotesize Stainless Steel] at (axis cs:0.18,0.74,0.08) {};
\end{ternaryaxis}
\end{tikzpicture}
\end{document}