problems = [449 262] ;
nprobs = length (problems) ;

for k = 1:nprobs

    Problem = UFget (problems (k))
    A = Problem.A ;
    [Ai Aj Ax] = find (A) ;
    [m n] = size (A) ;
    y = (1:m)' ;
    x = (n:-1:1)' ;
    z1 = A*x + y ;
    z2 = cs_gaxpy (A, x, y) ;
    err1 = norm (z1 - z2) / norm (z1)

    try

        Ai = int32 (Ai) - 1 ;
        Aj = int32 (Aj) - 1 ;
        z3 = cs_taxpy (Ai, Aj, Ax, x, y) ;
        err2 = norm (z1 - z3) / norm (z1)

        nz = length (Ax) ;
        p = randperm (nz) ;

        Ai = Ai (p) ;
        Aj = Aj (p) ;
        Ax = Ax (p) ;
        z4 = cs_taxpy (Ai, Aj, Ax, x, y) ;
        err3 = norm (z1 - z4) / norm (z1)

    catch
        lasterr
        fprintf ('something failed ...\n') ;
    end
end