[CSC 435] Matrices

[Andrew J. Pounds]

Guys -- while the direct linear solver does not have to have a 
diagonally dominant matrix to guarantee convergence (it does the row 
interchanges to obviate the need for that requirement) the iterative 
linear solver needs to have a diagonally dominant matrix "A" to 
/guarantee/ convergence.

Here is how I constructed my matrix A in my Fortran code to make sure I 
was close to diagonal dominance.


do i = 1, DIM
    do j = 1, DIM
    call random_number(ranval)
      if ( i .ne. j) then
        matrixa(j,i) = ranval
      else
        matrixa(j,i) = 2.0 * ranval * DIM
      endif
    enddo
enddo


-- 
Andrew J. Pounds, Ph.D.  (pounds_aj at mercer.edu)
Professor of Chemistry and Computer Science
Mercer University,  Macon, GA 31207   (478) 301-5627
http://faculty.mercer.edu/pounds_aj

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://theochem.mercer.edu/pipermail/csc435/attachments/20160323/662e2e23/attachment.html>