function F = poly_face(CON,k)% Project constraints onto one face of the polyhedral %% Syntax:%   "F = poly_face(con,k)"%% Description:%   "poly_face(con,k)" returns a new linear constraint object constructed%   by removing the "k"th face of "con" from the inequality constraint%   (CI,dI) and adding it to the equality constraint (CE,dE) of the new%   object.  This is accomplished by removing the "k"th row of CI and dI,%   adding this row to CE and dE, and then constructing a new linear%   constraint object using these modified constraint matrices.%% Examples:%   Given a linear constraint object "con" representing a cube with%   corners at (x1,x2,x3) triples (2,1,0), (2,1,2), (2,3,0), (2,3,2),%   (4,3,0), (4,3,2), (4,1,0), and (4,1,2).  If x3 = 0 is face number 5,%   then,   %%%%     "F = polyface(con,5)"%%%%   returns "F", a linear constraint object representing a square in the%   x3=0 plane with corners at (x1,x2) pairs (2,1), (2,3), (4,3), and%   (4,1).%%%% See Also:%   linearcon,number_of_faces[CE,dE,CI,dI] = linearcon_data(CON);N = length(dI);if (k <= N) & (k >= 1)  CEnew = [CE; CI(k,:)];  dEnew = [dE; dI(k,:)];  CInew = [CI(1:k-1,:); CI(k+1:N,:)];  dInew = [dI(1:k-1,:); dI(k+1:N,:)];  F = linearcon(CEnew,dEnew,CInew,dInew);else  disp('LINEARCON/FACE: Invalid face index given.')end