[gmx-users] RE: Regarding DCCM analysis with g_covar available in user contributed section

[Ran Friedman]

Hi,
As stated below the upper half of the triangle shows correlations having r>0.5 or r<-0.5, that is |r|>0.5
Ran

________________________________________
From: bipin singh [bipinelmat at gmail.com]
Sent: 12 March 2011 12:27
To: Discussion list for GROMACS users
Cc: r.friedman at bioc.uzh.ch
Subject: Regarding DCCM analysis with g_covar available in user contributed section

Hello,
I am using g_covar vailable in user contributed section (by Ran Friedman) the description available for the package is as follows:

"This package contains a modified version of g_covar, which can print a matrix
of atomic correlation coefficients (with -xpmc) and write all pairs with a
correlation > 0.5 to a log file (with -clog). Otherwise it is the same as the
original program.
The xpm correlation matrix shows only cross-correlations larger than 0.5
(absolute values) on the upper triangle and all values on the lower
triangle. Thus, the upper triangle displays only the most correlated motions."

As stated that the upper triangle only shows the cross-correlation greater than
0.5, but I am also getting some negative correlation values(blue regions) in above triangle.
I don't know what is the region behind this.
Plz help me to understand this behaviour.
I have attached my xpm matrix file generated using g_covar.
--
---------------------------------
Thanks and regards
Bipin Singh