code: function getLayoutAttrs(elmt) {
          
          var tab,
          i=0,N,
          l={};
          
          switch (elmt.tagName) {
              case 'circle' : tab = ['cx','cy','r']; break;
              case 'ellipse' : tab = ['cx','cy','rx','ry']; break;
              case 'rect' : tab = ['x','y','rx','ry','width','height']; break;
              case 'line' : tab = ['x1','y1','x2','y2']; break;
              case 'polygon' : case 'polyline' : tab = ['points']; break;
              case 'path' : tab = ['d']; break;
              default : tab = ['x','y','width','height']; break;		
          }
          
          for(N=tab.length;i<N;i++) l[tab[i]] = parseFloat(elmt.getAttribute(tab[i]) || 0);
          
          return l;
      }
docs: JSYG.kappa = 0.551915; 
  récupère les propriétés de mise en page