// knot32m.fe

// 3,2 torus knot with mobius band

parameter maj_r = 2
parameter min_r = 0.5

boundary 1 parameter 1 
x1:  cos(2*p1)*(maj_r + min_r*cos(3*p1))
x2:  sin(2*p1)*(maj_r + min_r*cos(3*p1))
x3:  min_r*sin(3*p1)

vertices
1    0.0*pi  boundary 1
2    0.2*pi  boundary 1
3    0.4*pi  boundary 1
4    0.6*pi  boundary 1
5    0.8*pi  boundary 1
6    1.0*pi  boundary 1
7    1.2*pi  boundary 1
8    1.4*pi  boundary 1
9    1.6*pi  boundary 1
10   1.8*pi  boundary 1

edges
1     1 2 boundary 1
2     2 3 boundary 1
3     3 4 boundary 1
4     4 5 boundary 1
5     5 6 boundary 1
6     6 7 boundary 1
7     7 8 boundary 1
8     8 9 boundary 1
9     9 10 boundary 1
10    10 1 boundary 1
11    1 6
12    2 7
13    3 8
14    4 9
15    5 10

faces
1    10 11 -5 15
2    11 6 -12 -1
3    12 7 -13 -2
4    13 8 -14 -3
5    14 9 -15 -4

read
fix vertex where on_boundary 1
fix edge where on_boundary 1

read
hessian_normal

// typical evolution
gogo := { refine edge where fixed; t .7;   // get more uniform triangulation
          r; g 5; r; g 5; hessian;
          r; g 5; hessian; hessian;
        }