3D data plotting from data acquisition

Hello, I am new to matlab and I am trying to 3D plot data from a .dat file in matlab. The format for the data file is as follows:

 xPosition    yPosition    zPosition    xData    yData    zData

each of these are vectors which have a dimension of (59464 x 1).

The problem I am having is associating the xPosition with xData, yPosition with yData, and the zPosition with zData. Here is the code I am using.

plot3(xPos,yPos,zPos,xField,yField,zField)
grid on

which gives me this plot

When I try to plot the data using plot3(), matlab doesn't know how to associate the data within these vectors, so what ends up happening is that all of the data is plotted at once.

I eventually want to have each xPos corresponding with xData (for y and z also). If there is any way to reformat the data so that I can use this for the contour plot and streamline functions this data set, please let me know. Thanks.

Answer 1

[Jacob Mathew]

Hey jim,

You could try plotting the data using the quiver3 method. This method lets you plot vectors with a head and a tail, letting you better analyse them. A simple example with some sample data is as follows:

% Number of vectors
numVectors = 10;

% Generate random positions (xPosition, yPosition, zPosition)
xPosition = rand(numVectors, 1) * 10; 
yPosition = rand(numVectors, 1) * 10; 
zPosition = rand(numVectors, 1) * 10; 

% Generate random vector components (xData, yData, zData)
xData = randn(numVectors, 1); 
yData = randn(numVectors, 1); 
zData = randn(numVectors, 1); 

% Plot using quiver3
figure;
quiver3(xPosition, yPosition, zPosition, xData, yData, zData, 'AutoScale', 'on');
xlabel('X');
ylabel('Y');
zlabel('Z');
title('3D Vector Field');
grid on;
axis equal;

You can refer to the documentation for quiver3 as follows:

https://www.mathworks.com/help/releases/r2024a/matlab/ref/quiver3.html