Plot 3d surface using cartesian coordinates

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I want to plot a surface like this one using cartesian cooridnates:
Those are my coordinates:
x=[0.6, 0.7, 0.4, 0.3, 10.0, 10.6, 10.7, 10.7, 20.6, ...]; %1x28
y=[0.3, 10.0, 20.4, 30.0, 0.0, 10.6, 20.2, 30.5, 0.6, ...]; %1x28
z=[-9.3, 3.3, -38.1, -11.6, -11.7, -12.5, -28.0, -73.1, ...]; %1x28
I've tried this code but I did not get right result:
[X,Y] = meshgrid(x,y);
Z = griddata(x,y,z, X, Y);
figure;
surf(X,Y,Z);
What is the best way to plot this surface?

Answers (2)

Star Strider
Star Strider on 18 Mar 2016
If you want to interpolate to a finer grid, you have to give it a finer grid to interpolate. You actually did not do any interpolation.
See if this does what you want:
x=[0.6, 0.7, 0.4, 0.3, 10.0, 10.6, 10.7, 10.7]; %1x28
y=[0.3, 10.0, 20.4, 30.0, 0.0, 10.6, 20.2, 30.5,]; %1x28
z=[-9.3, 3.3, -38.1, -11.6, -11.7, -12.5, -28.0, -73.1]; %1x28
xq = linspace(min(x), max (x));
yq = linspace(min(y), max (y));
[X,Y] = meshgrid(xq,yq);
Z = griddata(x,y,z, X, Y, 'cubic');
figure;
surf(X,Y,Z);
grid on
Experiment with the ‘method’ to get the result you want.

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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