function H1 = pivot(H,ip,jp)
% H1 = pivot(H,ip,jp)

% Contact: Tom Shores, tshores@math.unl.edu

[n,m] = size(H);
piv = H(ip,jp);
if piv == 0
	disp('singular')
else
	H(ip,:) = H(ip,:)/piv;
	for i = 1:n
		if i ~= ip
			H(i,:) = H(i,:) - H(i,jp)*H(ip,:);
		end
	end
end
H1 = H;