def test_dBdB(self): bs = BSpline(nknots=5) M = bs.deg + bs.nknots + 1 BB = np.zeros((M,M)) for i in xrange(-bs.deg, bs.nknots + 1): for j in xrange(i, bs.nknots + 1): BB[ix(i),ix(j)] = bs.dBdB(i, j) BB[ix(j),ix(i)] = BB[ix(i),ix(j)] print "matrix dBdB" print BB aI = 10e-6*np.eye(np.shape(BB)[0]) L = np.linalg.cholesky(BB + aI) print "Cholesky factor of matrix dBdB" print L print "sucess, matrix is 'almost' semidefinite" pass