Returns the number with the given continued fraction expansion.
fromcfrac( a )
% Return the number whose continued fraction coefficieints are given as a row or column vector.
% This vector may be taken as the first column vector of the output of
% cfrac, roundcfrac, QCF, or RoundQCF.
function fcf = fromcfrac( a )
len = length( a );
p2 = 0;
q2 = 1;
p1 = 1;
q1 = 0;
p = a(1);
q = 1;
for i=2:len
p2 = p1;
q2 = q1;
p1 = p;
q1 = q;
p = p1 * a(i) + p2;
q = q1 * a(i) + q2;
end
fcf = p/q;