Recent content by Abbas

  1. A

    MHB Condition Number of sum of Matrices

    I was looking for an answer since I post it here, cond(A+B) =< cond(A) + cond(B) is not always true. the hypothesis is wrong. Thanks BTW. :)
  2. A

    MHB Condition Number of sum of Matrices

    Thanks, but Are you sure if this is true? I doubt (A+B)-1= A-1+B-1. How about ||A-1||⋅||B||+||A||⋅||B-1|| ? can these terms be omitted?
  3. A

    MHB Condition Number of sum of Matrices

    As far as I know there is no explicit formulas but is this true? I've tested it in Matlab with random matrices and It seems true! cond(A+B) =< cond(A) + cond(B) Where can I find a proof for this hypothesis?
  4. A

    MHB Eigenvalues of similar matrices

    Thank You. So just the sequence of eigenvalues changes. The main Problem is: Det( diag(a1,a2,a3) + R diag(a1,a2,a3)RT - xI )=0 I rewrote it in this form: Det( R diag (a1,a2,a3)RT - x*I )=0 which means eigenvalues of R diag(a1,a2,a3)RT are the new parameter x*=x-diag(a1,a2,a3) can we say...