How to find data points from a 3D plotted graph in MATLAB

i have plotted a 3D bezier surface, i need to find values of Y for particular values of X and Z. how do i find it. Please hlep me its urgent.

here is my program

 Bx=[0 0;20 20;40 40;50 50;70 70;80 80;100 100];
By=[2.181 2.3;1.909 1.821;1.324 1.6; 1.168 1.5;1.85 1.646; 4.2 2.415; 5 3.112];
Bz=[0.4 0.2;0.4 0.2;0.4 0.2;0.4 0.2;0.4 0.2;0.4 0.2;0.4 0.2];
N = [1 -6 15 -20 15 -6 1; -6 30 -60 60 -30 6 0; 15 -60 90 -60 15 0 0; -20 60 -60 20 0 0 0; 15 -30 15 0 0 0 0; -6 6 0 0 0 0 0; 1 0 0 0 0 0 0];
M = [-1 1; 1 0];
i=1;
for u= linspace(0,1)
    for v= linspace(0,1)
        U=[u^6,u^5,u^4,u^3,u^2,u,1];
        V=[v,1];
        x(i)= U*N*Bx*M'*V';
        y(i)= U*N*By*M'*V';
        z(i)= U*N*Bz*M'*V';
        i=i+1;
    end
end
plot3(x,y,z)

Answer 1

[darova]

use griddata

y1 = griddata(X,Z,Y,x1,z1);

[abhinadan papnoi]

Thank you so much brother, it worked perfectly. You saved me.

[darova]

im jsut doing my job