rosser (MATLAB Functions)

Classic symmetric eigenvalue test problem

Syntax

```
A = rosser
```

Description

A = rosser returns the Rosser matrix. This matrix was a challenge for many matrix eigenvalue algorithms. But LAPACK's DSYEV routine used in MATLAB has no trouble with it. The matrix is 8-by-8 with integer elements. It has:

A double eigenvalue
Three nearly equal eigenvalues
Dominant eigenvalues of opposite sign
A zero eigenvalue
A small, nonzero eigenvalue

Examples

rosser

ans =

   611   196  -192   407    -8   -52   -49    29
   196   899   113  -192   -71   -43    -8   -44
  -192   113   899   196    61    49     8    52
   407  -192   196   611     8    44    59   -23
    -8   -71    61     8   411  -599   208   208
   -52   -43    49    44  -599   411   208   208
   -49    -8     8    59   208   208    99  -911
    29   -44    52   -23   208   208  -911    99

rose rot90