function [xo,yo]=cpRemove(x_cp,y_cp,A,k) %
% function [xo,yo]=cpRemove(x_cp,y_cp,A,k) Removes the kth control point, 
% using the refinement matrix A to repair the damage. 
 
[s1,s2]=size(A);
if s1 ~= 4 & s2 ~=5
   error('The size of A should be 4x5.');
end

if min(size(x_cp)) > 1
   error('The first input should be a vector.');
end
if min(size(y_cp)) > 1
   error('The second input should be a vector.');
end

if max(size(x_cp)) ~= max(size(y_cp))
   error('The first two vectors must have the same length');
end

s=max(size(x_cp));
xo=zeros(1,s-1);
yo=zeros(1,s-1);
xo(1:k-3)=x_cp(1:k-3);
yo(1:k-3)=y_cp(1:k-3);
xo(k+2:s-1)=x_cp(k+3:s);
yo(k+2:s-1)=y_cp(k+3:s);
xo(k-2:k+1)=x_cp(k-2:k+2)*A';
yo(k-2:k+1)=y_cp(k-2:k+2)*A';