Re: [ccp4bb]: problems with

["Fred. Vellieux" <vellieux@ibs.fr>]

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As far as I am concerned, if I am being translated by a vector
T=[+X]
  [+Y]
  [+Z]
then the "inverse operation" required to get me back to my initial state
is
-T=[-X]
   [-Y]
   [-Z]

This should also work with other objects!

Fred.

On Thu, 28 Mar 2002, OnLineHelpForm wrote:

> 
> Dear All
> 
> A rather naive question, I'm  afraid. I'm trying to determine the inverse
> of a large number of rotation/translation operations for some 
> coordinates, each operation represented as a 3x3 matrix and translation vector. I
> understand that if A -> A' by a particular operation, then the rotation
> matrix for A' -> A is the transpose matrix. But what how is the tranlation vector
> of the inverse operation calculated ? It is not simply the reverse
> vector. Also, are there any CCP4 programs which automate this procedure,
> rather than do them all by hand (or specifying INVERT in dm !)
> 
> 

-- 
s-mail: F.M.D. Vellieux (B.Sc., Ph.D.)
        Institut de Biologie Structurale J.-P. Ebel CEA CNRS UJF
        41 rue Jules Horowitz
        38027 Grenoble Cedex 01
        France
Tel:    (+33) (0) 438789605
Fax:    (+33) (0) 438785494
e-mail: vellieux@ibs.fr
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