Barycentric coodinates based Quadratic Serendipity shape function

This function produce Quadratic serendipity shape function using barycentric coodinate.

This function produce Quadratic serendipity shape function using barycentric coodinate.
The procedure for this shape function is proposed at 'Mathematics of computation, 2014, vol.83, no.290, pp2691-2716' Alexander Rand, et al.
They proposed this scheme for arbitrary polygon. And the generalized barycentric coordinate is used.
Especially, two type of Barycentric coodinates are fulfilled, Wachspress coordinate & Mean value coodinate.
There are 6 m-files in attached zip file.
- get_val_shape_fn_barycen.m : main function
- get_val_lambda.m : subfunction for calculating 'lambda'
- get_val_mu.m : subfunction for calculating 'mu (lambda * lambda)'
- get_val_xi.m : subfunction for calculating 'xi (extract some function to get serendipity family)'
- get_val_phi.m : subfunction for calculating 'phi (some modification for xi)'
- get_coord_vicinity_ab.m : subfurction for 'get_val_xi.m'