Nowadays
it is even hard to obtain datasets of simple examples. One reason is the absence
of published numerical data sets stored at some publishing house, or a data set
which accompanies a research article published in a scientific journal. This is
a serious drawback in the scientific validation of numerical experiments but
also leads to the more elementary drawback that models are not available, for
example, as initial data sets to perform own experiments. Often one would just
like to have a digital model with certain properties to test one's own numerical
algorithm or implementation.
Another aspect of an online model collection is the educational benefit. Geometry books usually contain only a few images, and students still have a hard time to find good visual material. The software JavaView provides a simple way for every scientist to have mathematical models at his fingertips.
For more information and an interactive applet, see here.