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## -*- texinfo -*-
## @deftypefn {} {@var{R} =} rosser ()
## Return the @nospell{Rosser} matrix.
##
## This is a difficult test case used to evaluate eigenvalue algorithms.
## @seealso{wilkinson, eig}
## @end deftypefn

function R = rosser ()

  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];

endfunction


%!assert (size (rosser ()), [8,8])
%!assert (rosser ()([1, end]), [611, 99])

%!error rosser (1)