Matrix: Nemeth/nemeth24

Description: Newton-Schultz iteration, Z_k+1=Z_k+(1/2)*(I-(Z_k)^2)*Z_k. This is Z_19

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• Matrix group: Nemeth
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• download as a MATLAB mat-file, file size: 12 MB. Use UFget(788) or UFget('Nemeth/nemeth24') in MATLAB.
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 Matrix properties number of rows 9,506 number of columns 9,506 nonzeros 1,506,550 structural full rank? yes structural rank 9,506 # of blocks from dmperm 1 # strongly connected comp. 1 explicit zero entries 0 nonzero pattern symmetry symmetric numeric value symmetry symmetric type real structure symmetric Cholesky candidate? no positive definite? no

 author K. Nemeth editor T. Davis date 1999 kind subsequent theoretical/quantum chemistry problem 2D/3D problem? no

Notes:

```next: Nemeth/nemeth25 first: Nemeth/nemeth01
```

 Ordering statistics: result nnz(chol(P*(A+A'+s*I)*P')) with AMD 798,379 Cholesky flop count 6.7e+07 nnz(L+U), no partial pivoting, with AMD 1,587,252 nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD 824,288 nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD 1,749,670

 SVD-based statistics: norm(A) 1 min(svd(A)) 0.996383 cond(A) 1.00363 rank(A) 9,506 sprank(A)-rank(A) 0 null space dimension 0 full numerical rank? yes

 singular values (MAT file): click here SVD method used: s = svd (full (A)) ; status: ok

For a description of the statistics displayed above, click here.

Maintained by Tim Davis, last updated 12-Mar-2014.
Matrix pictures by cspy, a MATLAB function in the CSparse package.
Matrix graphs by Yifan Hu, AT&T Labs Visualization Group.