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function R = rosser(classname) %ROSSER Classic symmetric eigenvalue test problem. % 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. % % ROSSER(CLASSNAME) produces a matrix of class CLASSNAME. % CLASSNAME must be either 'single' or 'double' (the default). % Copyright 1984-2005 The MathWorks, Inc. if nargin < 1, classname = 'double'; end R = [ 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.]; R = cast(R,classname);