## Numerical Analysis-help

For the discussion of math. Duh.

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evinda
Posts: 32
Joined: Fri May 03, 2013 10:16 pm UTC

### Numerical Analysis-help

Hey!! I have a question..Can the Jacobi method be applied for a Hilbert matrix,with dimension>=250..Because,when I do this,I get NaN as result..Has it to do with the method?Or have I done something wrong???
I hope someone can help me.....

jestingrabbit
Factoids are just Datas that haven't grown up yet
Posts: 5967
Joined: Tue Nov 28, 2006 9:50 pm UTC
Location: Sydney

### Re: Numerical Analysis-help

From WP

the Jacobi method is an algorithm for determining the solutions of a system of linear equations with largest absolute values in each row and column dominated by the diagonal element.

ie the diagonal has to be the biggest element in the row and column. Is this condition satisfied by the Hilbert matrix?
ameretrifle wrote:Magic space feudalism is therefore a viable idea.

evinda
Posts: 32
Joined: Fri May 03, 2013 10:16 pm UTC

### Re: Numerical Analysis-help

jestingrabbit wrote:From WP

the Jacobi method is an algorithm for determining the solutions of a system of linear equations with largest absolute values in each row and column dominated by the diagonal element.

ie the diagonal has to be the biggest element in the row and column. Is this condition satisfied by the Hilbert matrix?

No,the Hilbert matrix doesn't satisfy this condition!!!Has this to do something with the fact that I get NaN as result??

jestingrabbit
Factoids are just Datas that haven't grown up yet
Posts: 5967
Joined: Tue Nov 28, 2006 9:50 pm UTC
Location: Sydney

### Re: Numerical Analysis-help

evinda wrote:
jestingrabbit wrote:From WP

the Jacobi method is an algorithm for determining the solutions of a system of linear equations with largest absolute values in each row and column dominated by the diagonal element.

ie the diagonal has to be the biggest element in the row and column. Is this condition satisfied by the Hilbert matrix?

No,the Hilbert matrix doesn't satisfy this condition!!!Has this to do something with the fact that I get NaN as result??

I would expect so.
ameretrifle wrote:Magic space feudalism is therefore a viable idea.

evinda
Posts: 32
Joined: Fri May 03, 2013 10:16 pm UTC

### Re: Numerical Analysis-help

jestingrabbit wrote:
evinda wrote:
jestingrabbit wrote:From WP

the Jacobi method is an algorithm for determining the solutions of a system of linear equations with largest absolute values in each row and column dominated by the diagonal element.

ie the diagonal has to be the biggest element in the row and column. Is this condition satisfied by the Hilbert matrix?

No,the Hilbert matrix doesn't satisfy this condition!!!Has this to do something with the fact that I get NaN as result??

I would expect so.

Nice Could you also tell me how much is the the spectral radius of the iteration matrix of a 250x250 Hilbert matrix,so I can check my result?