MATLAB: Plotting a 3D scalar field as a coloured 3D scatter graph

Question

Hello,

I have a 3D temperature data set: a 3D array giving the temperature at each point in a 3D cartesian space, with coordinates x, y, z. I would like to find a way of visualising this data set. I thought it would be straightforward to plot a 3D scatter graph, and at each point on the graph the temperature is represented by a colour. However, I'm not sure how to use the scatter3 function.

Can anyone please help me to plot this data?

Specifically my data is:

x=linspace(-0.3,0.3,16); y=linspace(-0.3,0.3,16); z=linspace(-0.3,0.3,16);

Then I have a 3D array, Temperature(x,y,z) which has a different value for each set x,y,z.

Thanks.

Answer 1

If you want to use scatter3, you can pass it your x, y, and z vectors which will define where markers will be drawn. Then your temperature data can be used to control the size and/or color of the markers. According to your description, x, y, and z are vectors whereas Temperature is a 3D array. That seems slightly odd, but I suppose plausible. At any rate, you'd need to at least convert that 3D array into a vector before passing it to scatter3:

scatter3( x, y, z, [], Temperature(:) ); % Use Temperature to set marker color

That makes some assumptions about how the data is actually stored, but it's a best guess based on the information you've given.

If you have a lot of data points, then scatter3 isn't the best option.