function qualiteindiv(A,i,j);								
//projection des individus dans le plan i-j
  xset("font",4,3);
  Coord=acpindiv(A);
  deltax=(max(Coord(:,i))-min(Coord(:,i)))/15;
  xmin=min(Coord(:,i))-deltax;
  xmax=max(Coord(:,i))+deltax;
  deltay=(max(Coord(:,j))-min(Coord(:,j)))/15;
  ymin=min(Coord(:,j))-deltay;
  ymax=max(Coord(:,j))+deltay;
  
  plotframe([xmin,ymin,xmax,ymax],[2,10,2,10],[%f,%f],..
  ["Projection sur le plan "+string(i)+"-"+string(j),"",""]);
  
  X=reduire(A);
  deff('[y]=qual_p(k)','y=( norm(Coord(k,[i,j])) / norm(Coord(k,:)))^2')
  n=size(A,"r");
  Q=feval(1:n,qual_p);

  G=find(Q>0.9);
  M=find(Q<0.9&Q>0.7);
  B=find(Q<0.7);
  for h=G,
	xrects([Coord(h,i);Coord(h,j);0.2;0.2],3);
  end;
  for h=M,
	xrects([Coord(h,i);Coord(h,j);0.1;0.1],2);
  end;
  for h=B,
	xrects([Coord(h,i);Coord(h,j);0.05;0.05],1);
  end;
  xrects([xmin;ymin-0.7;0.2;0.2],3);
  xstring(xmin+0.5,ymin-0.9,"cos^2>0.9")
  xrects([xmin+2;ymin-0.7;0.1;0.1],2);
  xstring(xmin+2.5,ymin-0.9,"0.7<cos^2<0.9")
  xrects([xmin+5;ymin-0.8;0.05;0.05],1);
  xstring(xmin+5.2,ymin-0.9,"cos^2<0.7")
  
  n = size(Coord,"r");  
  for l=1:n,
    xstring(Coord(l,i),Coord(l,j),string(l));
  end;
  
endfunction;