Plot xyz point data to 3D contour

How to plot the xyz point data (attached) into 3D contour? Thank you

[Amra Rajuli]

the xy data is not evenly space or irregular

Answer 1

[Star Strider]

Try this:

D = readmatrix('data.txt');

x = D(~(any(isnan(D),2)),1);
y = D(~(any(isnan(D),2)),2);
z = D(~(any(isnan(D),2)),3);

N = 50;
xv = linspace(min(x), max(x), N);
yv = linspace(min(y), max(y), N);
[X,Y] = ndgrid(xv, yv);
Z = griddata(x, y, z, X, Y);

figure
surf(X, Y, Z)

.

[Amra Rajuli]

thank you very much for your help.. I am so sorry for being late in responsing your answer..

[Star Strider]

As always, my pleasure!

No worries! I very much appreciate that you returned to check on it and Accept my Answer!

[Amra Rajuli]

what if the input is shape file. your code would be:

D = shaperead('Cross_9_Agustus_2020_A1.shp')

x = D.X(~(any(isnan(D),2)),4);!starting error
y = D.Y(~(any(isnan(D),2)),5);
z = D.Z(~(any(isnan(D),2)),6);
N = 100;
xv = linspace(min(x), max(x), N);
yv = linspace(min(y), max(y), N);
[X,Y] = ndgrid(xv, yv);
Z = griddata(x, y, z, X, Y);
figure
contour(X, Y, Z,10);

however, it was written in error part that:

Undefined function 'isnan' for input arguments of type 'struct'.

do you familiar with that problem? Thank you in advance

[Star Strider]

The shaperead function requires the Mapping Toolbox, that I do not have.

I cannot run your code.

However, removing the NaN values from the structure would likely be straightforward:

Dnonan = structfun(@(x)x(~(any(isnan(x),2))),D, 'Unif',0); 
x = Dnonan.X;
y = Dnonan.Y;
z = Dnonan.Z;

See if that does what you want. (It worked with a random structure I created to test this, with the fields of ‘D’ being column vectors.)

Make appropriate changes to get thee result you want.