function I = and(v1,v2)% Find the intersection of two vertices objects %% Syntax:%   "V = and(a,b)"%%   "V = a & b"%% Description:%   "and(a,b)" returns a vertices object constructed from all points%   contained in both "a" and "b".  "b" can be given as a list of points%   which is then converted to a vertices object before finding the%   intersection.%% Examples:%   Given two vertices objects, "a" representing a square in the x3 = 0%   plane with corners at (x1,x2) pairs (2,1), (2,3), (4,3), and (4,1)%   and "b", another square in the same plane with corners at (2,1),%   (2,2), (3,1), and (3,2),%%%%   "V = and(a,b)"%%%%   returns "V", a vertices object containing the (x1,x2) pair (2,1). %% See Also:%   verticesI = vertices; % assumeif ~isa(v2,'vertices')  v2 = vertices(v2);endif isempty(v1) && isempty(v2) && (dim(v1) ~= dim(v2))  disp('VERTICES/OR: different dimensions given')  returnend  point_tol = parameters.poly_point_tol;if isempty(v1) || isempty(v2)  returnendN1 = length(v1);N2 = length(v2);list = v1.list;isInV2 = false(N1, 1);for k = 1:N1  v1k = v1.list(:,k);  for l = 1:N2    v2l = v2.list(:,l);    diff = (v1k-v2l);    if (diff'*diff < point_tol)      isInV2(k) = true;      break;    end  endendlist = list(:,isInV2);I = vertices(list);