This function creates simple violin plots by estimating the kernel density, using matlabs default ksdensity(). Given a matrix or table with m columns, you will get violins for each of the columns.
Key Features:
a) Specify plotting features as facecolor, edgecolor, etc.
b) Provide data with variable column length as cells if wanted, e.g. Y = [100x1 double] [10x1 double]
c) Plot Violins on the desired x-position

Notes:

1) This function is not perfect. Please modify it as you like.

2) Please do consider the function by Jonas: "Violin Plots for plotting multiple distributions (distributionPlot.m)" which gets you the histograms as shape.

3) Please note: Kernel density is estimated with ksdensity which uses a gaussian kernel by default. Although the bandwidth is optimal according to the rule of thumb, it is however estimated separately for each violin. For publications, etc., please consider that you might need to use the same kernel bandwidths for all data-subsets in order to be able to really compare the distributions.

A beautiful example is given here:
http://www.matlabtips.com/beautiful-plots-in-matlab/