Changes

         function indexinterpolate(obj,i) { return  (obj[i] != undefined) ? obj[i] : obj};  

         function indexinterpolate(obj,i) { return  (obj[i] != undefined) ? obj[i] : obj};  

         // helper function for checking a part of an array exists

         // helper function for checking a part of an array exists

         function indexcheck(obj,i) {  return  (obj[i] != undefined) ? obj[i] : undefined };

         function indexcheck(obj,i) {  if ( obj != undefined) { return  (obj[i] != undefined) ? obj[i] : undefined } };

         // dive selects matrix.a.b.c.d from the array called matrix and 'a.b.c.d' as string

         // dive selects matrix.a.b.c.d from the array called matrix and 'a.b.c.d' as string

         // if a.b.c.d does not exists, it returns the substructure until the substructure exists, if d does not exist, it returns matrix.a.b.c e.g.

         // if a.b.c.d does not exists, it returns the substructure until the substructure exists, if d does not exist, it returns matrix.a.b.c e.g.