How do I plot a contour line around a series of data points?

I have a series of data points indicating the performance for a range of different generic material types, and I want to plot a contour line around those points for illustrating the range of performance for a given material type, as in the image below.

Is plotting a graph/chart like this possible in Matlab? The data is stored as a series of numeric matrices.

[Star Strider]

You could do that with an area or patch plot, but it would not be trivial.

Answer 1

[Walter Roberson]

You need a scattered interpolant such as http://www.mathworks.com/help/matlab/ref/scatteredinterpolant-class.html or http://www.mathworks.com/help/matlab/ref/triscatteredinterp.html. Then you can use contourf(). However, in R2014b or later you might have difficulty using transparency if you use contourf()

Answer 2

[David MERCIER]

You can have a look at this kind of plot: Cluster Using Gaussian Mixture Models

[David MERCIER]

A possible function to use is this one: 54568-clustering-with-gaussian-mixture-models-gmms. Then, contourf or isosurfaces... is a simple way to encapsulate or surround cloud/cluster of points with a rounded shape.