3d plot from a x y z colum .txt file

Hello I´m a mechanichal engineering student and I´m a total beginner in Matlab. I have a .txt file with 3 columns (x,y,z data) taken from Leica and Confocal Uniovi Image software. And i need to import that .txt file and 3d plot it but as said I´m totally noob and dont have any ideo how to start.

Also, I need to import more than one .txt and compare them (to measure the tool wear in a CMC grinding wheel

Any help is welcome.

Thanks

Answer 1

[Cris LaPierre]

Great starting place is MATLAB Onramp. It covers the besics of using MATLAB, including importing data and getting help. It doesn't cover 3D plotting, but you can't do that until you get the data into MATLAB.

Once the data is in MATLAB, consider exploring the interative Create Plot live task. Do you know what type of 3D plot you want to create? You might be interested in scatter3. If you want to creaet a mesh or surface, you likely need to do some reshaping of your data.

[Adrián Tomillo Jorge]

Hello, thanks for answering, my teacher asked me to investigate around point cloud and point cloud registering

[Cris LaPierre]

Sounds like scatter3 will do what you need.

[Adrián Tomillo Jorge]

I found this:

data = readmatrix('Herramienta_1_1.txt');

x = data(:, 1);

y = data(:, 2);

z = data(:, 3);

% Plot 3-D point cloud.

subplot(1, 2, 1);

scatter3(x, y, z, 1);

grid on;

xlabel('X', 'FontSize', 15);

ylabel('Y', 'FontSize', 15);

zlabel('Z', 'FontSize', 15);

title('3-D Point Cloud', 'FontSize', 15);

But now all points display the sema colour. how can I change that?

Also, is there any way to plot 2 files and compare them?

[Cris LaPierre]

Ch 9 of MATLAB Onramp covers this, but yes, use hold on and hold off.

You do not need to use subplot unless you have a 2nd graph you want to include in the same figure.

You can specify color as an optional input to scatter3.

• scatter3(X,Y,Z,S,C)

Take a look at the examples on the documentation page, as well as the description of this input.

[Adrián Tomillo Jorge]

Thank you very much, I will look at it ;)