3d plot from knows XYZ

Hello, i have known list of numbers:

x = [0 10 20 30 0 10 20 0 10 20 30];

y = [0 0 0 0 15 15 15 15 30 30 30 30];

t = [20 22 25 23 22 27 30 25 19 20 18 22];

I used: [X,Y] = meshgrid(x,y), but i'm struggeling with understanding what to do with those t values.

thank you

Answer 1

[Star Strider]

It will be necessary to interpolate them to create a surface.

There are seeral ways to interpolate them, my favourite being the scatteredInterpolant function.

Try something like this —

x = [0 10 20 30 0 10 20 0 10 20 30];
y = [0 0 0 0 15 15 15 15 30 30 30 30];
t = [20 22 25 23 22 27 30 25 19 20 18 22];

Q = [size(x); size(y); size(t)]

Q = 3×2

1 11 1 12 1 12

y = y(1:numel(x));
t = t(1:numel(x));

xv = linspace(min(x), max(x), numel(x));
yv = linspace(min(y), max(y), numel(y));
[X,Y] = meshgrid(xv,yv);

F = scatteredInterpolant(x(:),y(:),t(:));

Warning: Duplicate data points have been detected and removed - corresponding values have been averaged.

T = F(X,Y);

figure
surfc(X, Y, T)
colormap(turbo)
colorbar
xlabel('X')
ylabel('Y')
zlabel('T')

EDIT — Added axis labels.

.

[Walter Roberson]

Note: the duplicate point is because the middle "30" is missing in x, so the 0 of the next x cycle lines up with the 15 of the end of the existing y cycle

0 10 20 0

15 15 15 15

whereas if the 30 had not been missed then it would have been (30,15) for that point instead of a second (0,15)

[Star Strider]

@Walter Roberson — That is also likely the origin of the vectors not having equal lengths. I just went with the available data.

I’m also assuming that May wants a surf plot because of the meshgrid call.

Answer 2

[Devargya chakraborty]

first of all, your vectors should be of the same length.

after that you can use the plot3 command to plot the graph or meshgrid also.

plot3(x,y,t);

meshgrid(x,y,t);