Two Hadamard Numbers for Matrices A discussion is given of two functions of the entries of a square matrix, both related to Hadamard's determinant theorem, which have some merits as alternatives to norm-bound "condition numbers." One (for linear systems) is known; the other (for eigen systems) seems to be new. CACM January, 1975 Birkhoff, G. matrices, eigenvalues, norms, condition numbers, error analysis, Gram-Schmidt orthogonalization 5.11 5.14 CA750105 JB January 12, 1978 10:37 AM 2806 5 2806 2806 5 2806 2806 5 2806