Connectivity data with PLV and PTE

Hello expert,

I did whole-brain connectivity analysis using PLV and PTE algorithms with D-K atlas. The D-K atlas divided the brain into 68 * 68 regions. I got the data, in PTE: 4624 * 1 * 6, I know that 4624=68 * 68, 6 refers to 6 frequency bands. However, in the PLV data, it is 2346 * 1 * 6. I donnot know why it is 2346 rather than 4624? Could you please kindly help me interpret the PLV data(2346 * 1 * 6)?

Thank you so much,

Yu

The PLV measure is symmetrical, therefore only half of the values are saved in the file.
See these forum posts:

http://neuroimage.usc.edu/forums/showthread.php?1796-How-the-Corr-matix-is-saved

Great! Thank you so much, Francois!