已知x,y坐标以及对应的z值，但z值中有空值，怎样进行曲面拟合，并得到拟合后对应的z值呢？
如x=[1,2,3,4,5,6,7,8,9,10]
y=[1,2,3,4,5,6,7,8,9,10]
z=[1,2,4,6,8,9,4,4,5,6;
2,3,3,5,8,9,7,NaN,7,6;
2,3,4,2,4,6,7,4,7,8;
3,4,6,7,3,7,5,4,7,5;
5,7,3,3,5,6,3,5,7,5;
3,5,7,7,4,6,3,6,8,5;
4,5,7,5,NaN,5,4,6,4,6;
4,5,5,3,3,8,6,5,7,5;
4,5,5,5,3,2,8,6,5,4;
6,7,4,8,3,7,3,5,4,3;]
求教，感激不尽呐！