3D surface plot out of points

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Vuk Radovic
Vuk Radovic on 22 Feb 2018
Answered: Shivam Anand on 11 May 2022
I am having trouble trying to make a surface plot out of given points.
I have a matrix Nx3 where each row represents X,Y,Z coordinates of points.
I would like to create something that resembles a surface plot, but I can not convert my Z into a matrix.
Can anyone help me, please?

Answers (2)

KSSV
KSSV on 23 Feb 2018
You need to use delaunayTriangulation. Your data is a scattered data. You need to mesh it with triangles and then plot as a surface. Check the below example code.
data = rand(100,3) ;
x = data(:,1) ; y = data(:,2) ; z = data(:,3) ;
dt = delaunayTriangulation(x,y) ;
tri = dt.ConnectivityList ;
xi = dt.Points(:,1) ; yi = dt.Points(:,2) ;
F = scatteredInterpolant(x,y,z);
zi = F(xi,yi) ;
trisurf(tri,xi,yi,zi)
view(2)
shading interp

Shivam Anand
Shivam Anand on 11 May 2022
x=[32 20 67 1 98 34 57 65 24 82 47 55 8 51 13 14 18 30 37 39 10 33 21 26 38 81 83 60 95 22 17 5 72 46 99 52 12 25 96 29 70 85 43 69 19 78 97 31 89 53 2 91 48 71 61 15 36 84 94 50 11 80 6 7 49 74 9 88 40 79 27 68 73 64 63 59 86 23 35 58 45 28 100 42 93 87 16 90 41 66 54 92 77 4 62 76 75 56 3 44];
y=[96 75 24 9 83 49 27 77 3 23 17 31 40 13 7 52 51 21 98 47 64 79 78 91 44 16 15 100 84 99 63 68 70 30 54 76 97 73 33 5 88 8 71 66 62 25 60 42 72 45 18 11 28 59 89 65 10 55 69 81 12 26 20 95 87 41 74 50 93 22 43 90 14 34 82 35 56 38 80 32 1 57 6 36 37 61 29 58 2 48 4 46 67 53 92 86 94 19 39 85];
z=[55 31 11 45 83 36 86 49 15 57 42 46 8 94 88 47 54 81 98 41 32 35 56 85 9 89 37 60 23 62 67 100 78 76 73 80 10 20 68 34 77 93 1 63 53 12 22 99 91 40 84 24 33 3 43 19 92 97 6 82 64 25 26 79 95 4 44 58 5 21 70 29 65 87 96 90 51 14 18 2 72 28 71 39 52 7 27 59 50 61 48 30 66 69 17 13 74 16 75 38];
xlin = linspace(min(x), max(x), 100);
ylin = linspace(min(y), max(y), 100);
[X,Y] = meshgrid(xlin, ylin);
% Z = griddata(x,y,z,X,Y,'natural');
% Z = griddata(x,y,z,X,Y,'cubic');
Z = griddata(x,y,z,X,Y,'v4');
mesh(X,Y,Z)
axis tight; hold on
plot3(x,y,z,'.','MarkerSize',15)

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