PDB CG3 - PDB - Calculate center of gravity

PURPOSE

Determine coordinates of center of gravity of atomic coordinates in a PDB file.   Example.

SEE ALSO

PDBIF	[PDB - Find information]
PDBPTS	[PDB - Put coordinates in SPIDER document file.]
PDBRT3	[PDB - Rotate by Euler angles in 3D space]
PDBRT3A	[PDB - Rotate by Euler angles around arbitrary center]
PDBRT3L	[PDB - Rotate PDB file around line]
PDBSH	[PDB - SHift coordinates]
PDBSTP	[PDB - Create PDB file from coordinate list]

USAGE

.OPERATION: PDB CG3 [xcp],[ycp],[zcp], [xcs],[ycs],[zcs], [na]

[This operation can return up to seven optional register variable:

Variable	Example	Receives
First	[xcp]	X Center of gravity in PDB coordinates
Second	[ycp]	Y Center of gravity in PDB coordinates
Third	[zcp]	Z Center of gravity in PDB coordinates
Fourth	[xcs]	X Center of gravity in SPIDER coordinates in units of Angstroms
Fifth	[ycs]	Y Center of gravity in SPIDER coordinates in units of Angstroms
Sixth	[zcs]	Z Center of gravity in SPIDER coordinates in units of Angstroms
Seventh	[na]	Total numbers of counted atoms

.INPUT FILE: img.pdb
[Enter the name of the PDB file with extension.]

NOTES

1. The coordinates should be divided by pixel size if the coordinates are expected in the unit of pixel.

2. Implemented by Zhong Huang, Pawel A. Penzcek.

SUBROUTINES

PDB

CALLER

DRIV1