[gmx-users] defined least squares plane

[nicolis at guideo.fr]

I am also interested for the answer.
I wanted to measure the angle between two phenyl rings and I only managed to define two 3-atom planes, one for each ring, and follow this angle with g_sgangle. I repeated with different sets of 3-atoms to have various estimations of the variations, but of course it is not as satisfactory as a least square plane computed from the 6 atoms of the ring.
On the other hand, if it is not included in the programs it should not be very complicated to program. All the coordinates are in the .trr? I see the formulaes to use given the xyz of the atoms but I did not yet looked at the manual to see how to access the xyz's.
Yiannis


At 10:10 +0900 5/01/02, Jang Seokyoung wrote:
Hi.
 
Can someone enlighten me how to build ' least squares plane ' of 7 atoms ?
 
I wanna to mesure the angle of the vector of two atoms and least squares plane of 7 atoms during MD simulation.
 
but, g_sgangle is only to define plane of 3 atoms.
 
Are we able to define least squares plane of 7 atoms during MD simulation or there are special technics?