Characteristic map of Loop subdivision

From SurfLab

Equations

Latex code

\begin{align}
    n := \mbox{valence}, \quad
    c := \cos{2\pi \over n}, \quad
    s := \sin{2\pi \over n}, \quad
\end{align}
\begin{align}
    x =
    \left[
    \begin{matrix}
        0                                                 \\
        { 1 \over 3 }(1+c)                                \\
        { (1+c)(26 + 30c + 4c^2) \over 30 + 54c + 24c^2 } \\
        c                                                 \\
    \end{matrix}
    \right]
\end{align}
\begin{align}
    y =
    \left[
    \begin{matrix}
        0                                             \\
        {1 \over 3 } s                                \\
        { s (26 + 30c + 4c^2) \over 30 + 54c + 24c^2} \\
        s                                             \\
    \end{matrix}
    \right]
\end{align}