**double_c_data**,
a MATLAB code which
can create, plot, or save a "double C" dataset.

The data is confined to two separate regions, each having the shape of the letter "C". The two regions are close, and interlocking, but do not actually touch. This data represents a difficult challenge for algorithms that attempt to detect natural segmentations of data.

The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.

**double_c_data** is available in
a MATLAB version.

image_components, a MATLAB code which seeks the connected "nonzero" or "nonblack" components or "segments" of an image or integer vector, array or 3D block.

kmeans, a MATLAB code which contains several different algorithms for the K-Means problem.

martinez, a dataset directory which contains datasets for computational statistics, including cluster analysis;

mds, a dataset directory which contains datasets for M-dimensional scaling;

ring_data , a MATLAB code which can create, plot, or save data generated by sampling a number of concentric, possibly overlapping rings.

sammon_data, a MATLAB code which generates six sets of M-dimensional data for cluster analysis.

- double_c_data.m, computes a double C dataset given N1 and N2.
- double_c_plot.m, plots a double C dataset.
- double_c_data.m, writes a double C dataset to a file.