function [cx,rot]=trans(cx,model,im);
%
% TRANS is called from COKRI2. It takes as input original coordinates and
%       return the rotated and reduced coordinates following specifications
%       described in model(im,:)
% Rotations are all performed anticlockwise with the observer located on the positive side of 
% the axis and looking toward the origin. In 3D, rotations are performed first along z,
% then along rotated y and then along twice rotated x.
% Author: D. Marcotte
% Version 2.1  97/aug/18

% some constants are defined

[n,d]=size(cx);
[m,p]=size(model);

% check for 1-D or isotropic model

if p-1>d,

   % perform rotation counterclockwise

   if d==2,
      ang=model(im,4); cang=cos(ang/180*pi); sang=sin(ang/180*pi);
      rot=[cang,-sang;sang,cang];
   else

      % rotation matrix in 3-D is computed around z, y and x in that order

      angz=model(im,7); cangz=cos(angz/180*pi); sangz=sin(angz/180*pi);
      angy=model(im,6); cangy=cos(angy/180*pi); sangy=sin(angy/180*pi);
      angx=model(im,5); cangx=cos(angx/180*pi); sangx=sin(angx/180*pi);
      rotz=[cangz,-sangz,0;sangz,cangz,0;0 0 1];
      roty=[cangy,0,sangy;0 1 0;-sangy,0,cangy];
      rotx=[1 0 0;0 cangx -sangx;0 sangx cangx];
      rot=rotz*roty*rotx;
   end

   % rotation is performed around z, y and x in that order, the other coordinates are left unchanged.

   dm=min(3,d);
   cx(:,1:dm)=cx(:,1:dm)*rot;
   t=[model(im,2:1+dm),ones(d-dm,1)];
   t=diag(t);
 else
   t=eye(d)*model(im,2);
end

% perform contractions or dilatations (reduced h)

  cx=cx/t;