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Homework #1
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Exercise 3.7 Is A diagonally dominant? #41

Closed acordonez closed 8 years ago

acordonez commented 8 years ago

Is matrix A in problem 3.7 strictly diagonally dominant (32x32 array of 1's with -5 on the main diagonal)? It doesn't seem like it is to me, but maybe I'm misunderstanding the definitions I've found online or the conditions under which the functions in exercise 3 should work.

mvelegar commented 8 years ago

The matrix A has 5 diagonals only: -5's along the main diagonal and 1's along the -2, -1, +1, and +2 subdiagonals. So for any row i |a_ii|=5>sum of the absolute value of 4 off diagonal elements=4. A is SDD.

acordonez commented 8 years ago

Ok, I see that. Thank you!