オーサグラフ
x = 2 π ⋅ 2 + cos  λ 2 + tan  φ { λ − sin − 1  ( sin  λ 3 ) } {\displaystyle x={\frac {2}{\pi }}\cdot {\frac {2+\cos \lambda }{{\sqrt {2}}+\tan \varphi }}\left\{\lambda -\sin ^{-1}\left({\frac {\sin \lambda }{\sqrt {3}}}\right)\right\}}
y = 1 3 ( 2 − 2 + cos  λ 2 + tan  φ ) {\displaystyle y={\frac {1}{\sqrt {3}}}\left({\sqrt {2}}-{\frac {2+\cos \lambda }{{\sqrt {2}}+\tan \varphi }}\right)}