48/50 Linear System Solver

[Thomas Klemm]

(02-16-2014 06:00 PM)Dieter Wrote:  What does it return if you try to evaluate the determinant? Something very close to (but not equal to) zero?

Exactly 0. The RANK of the matrix gives 2.
When flag -22 is cleared (Infinite -> error) I get an error (Infinite Result) when I use / or 1/x to solve the equation. However I get Tim's result when the flag -22 is set or when I use LSQ or the linear solver. But when you calculate the residual with RSD you will notice that the computed solution isn't close to an actual solution. Furthermore the condition number is huge: 9.8e15. The approximate number of accurate digits is thus 0. When the flag -22 is cleared I get the same error: Infinite Result.

We get a slightly different result when the last equation is replaced by 4*Ⅰ-3*Ⅱ:
-2x + y + 7z =-6

Now we get a real solution which can be checked with the residual.

Cheers
Thomas