How do I create a 2-D or 3-D line that changes colors along the data points?

I would like to plot a 2-D or 3-D line plot so that the colors change as the amplitude along the axes increases.

I would like to know how to produce a 3-D plot that uses the colormap for shading.

Answer 1

[MathWorks Support Team]

The MATLAB function, "plot3c.m", mimics the MESH command in a creative way to make a 2-D or 3-D line plot. Similar to how the mesh plot uses the colormap for shading, the color of the line will change with respect to the value of the specified axis in the "plot3c.m".

You can find the file at the following location:

https://www.mathworks.com/matlabcentral/fileexchange/5735-plot3c

Here is an example that uses this function to create a 2-D line of discrete markers that changes color with it's amplitude:

t = linspace(0,5*pi,100);
y=sin(t);
plot3c(t,y,0*t,y);
view(2)
colorbar

Here is an example that creates a scatter plot:\n

t = linspace(0,2*pi,40);
x = sin(t);
y = cos(t);
z = t.*x.^2;
plot3c(x,y,z,t,'x');

Alternatively, you may be interested in the SCATTER or SCATTER3 command. These can create scatter plots with point of varying colors. See the documentation for more information on these commands.

In addition the following file at the Matlab file exchange:\n

http://www.mathworks.com/matlabcentral/fileexchange/loadFile.do?objectId=9519&objectType=file

also provides an alternative efficient plotting routine that calls the PLOT3 routine only once for each group of points that map to the same color.