Wachspress Coordinates

• \(\displaystyle w_i=\frac{A_{i+1}+A_i-B_i}{A_{i+1}\,A_i}\)

• \(\displaystyle w_i=\frac{cot(\alpha_{i-1})+cot(\beta_i)}{\|p_i-p\|}\)

• Introduced in 1975, Eugene Wachspress, A Rational Finite Element Basis.

• (-) Limited to 2D
• (-) Limited to convex polygons (negative weights, poles)