Supplementary information to:

Family-based clusters of cognitive test performance in familial schizophrenia

F. Hoti, A. Tuulio-Hendriksson,J. Haukka, T. Partonen,
L. Holmström, and J. Lönnqvist

Comparison of Cluster 1 (well-performing) and Cluster 2 (impaired). The original variables (neuropsychological test variables + age) are visualized using the parallel coordinate plot. The subjects classified as well-performing are colored green and those classified as impaired are colored red. Yellow indicates overlap of green and red. There is overlap in all the original variables.

Click to enlarge (68 kb)

A parallel coordinate plot of the data after a rotation transformation in the data space. The axes correspond now to linear combinations of the original variables. The 6th axis from the top shows an interesting one-dimensional projection of the data. In this direction the two clusters are well separated.

Click to enlarge (70 kb)

The above figures where produced using the Crystal Vision software. The software uses a so-called grand tour technique to systematically (and in a continous manner) go through all possible rotations in the data space. The tour can be visually monitored using the parallel coordinate plot.

A movie which demonstrates the use of the software can be downloaded here.
High resolution CrystalVision.avi(44 Mb)
Smaller resolution CrystalVision.mpg(0.86 Mb)

Reference for Crystal Vision software