double surface using scatteredInterpolant

Hi,

I'm trying to make a 3-D plot with contour from a datafile that contains 1500 point in 3 column {x,y,z}, where z=f(x,y). The following code is what I use to generate the plot, and a,b contains the x,y of my file. As you can see from the following images in the 3d plot there's the overlap between two surface: a curved one (it's the one that should be my funciton) and a "roof" over it given by the parasite linear surface. Indeed, also the contour plot show the overlap between this surface. I cannot use scatter3 function because I need the contour plot that can be done only with an interpolation function of my data. How can I solve it? I'm quite new to matlab. Thanks.

load zoccolo.txt
a = zoccolo(:,1);
b = zoccolo(:,2);
z = zoccolo(:,3);

[X Y] = ndgrid(a,b);
F=scatteredInterpolant(a,b,z);
Z = F(X,Y);
tmp = surf(X,Y,Z);
rotate(tmp,[0 0 1],180)

contour(X,Y,Z,100);

Answer 1

[KSSV]

T = readtable('https://in.mathworks.com/matlabcentral/answers/uploaded_files/1065115/zoccolo.txt') ;
zoccolo = table2array(T) ;
a = zoccolo(:,1);
b = zoccolo(:,2);
z = zoccolo(:,3);
x = linspace(min(a),max(a));
y = linspace(min(b),max(b));
[X,Y] = meshgrid(x,y) ;
Z = griddata(a,b,z,X,Y) ; 
surf(X,Y,Z)

[JustANickName]

It works like a charm, thanks!