Re: large sparse matrix

[Carlo de Falco]

2009/9/1 Carlo de Falco <address@hidden>:

>> Also, what does the code
>>
>> [R, p, q] = chol(A);
>> nnz(R)
>>
>
>> work for Octave and Matlab?
>
> I tried this in Octave, after 30 min it did not finish yet...
> I will only be able to try it on Matlab tomorrow.
>
>> If so what is the value of NNZ of the factorization in both cases.

I killed the Octave after it had been running more than one hour and
produced no result.
In Matlab it ran in less than a second and the result was:

>> [R,p,q]=chol(A);
>> nnz (R)
ans =
     1368019
>> issparse (R)
ans =
     1
>> nnz(R)/prod(size(A))
ans =
     7.035863106552923e-03

Thanks,
c.