MATLAB Function Reference

rosser

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