function [matrix, matrixInfo] = pam90
%PAM90 substitution matrix in 1/2 bit units,
%   Expected score = -2.26, Entropy = 1.30 bits
%   Lowest score = -10, Highest score = 13
%
%   Order:
%   A  R  N  D  C  Q  E  G  H  I  L  K  M  F  P  S  T  W  Y  V  B  Z  X  *
%
%   [MATRIX,MATRIXINFO] = PAM90 returns a structure of information about
%   the matrix with fields Name, Scale, Entropy, ExpectedScore, LowestScore,
%   HighestScore and Order.

% Source:  ftp://ftp.ncbi.nih.gov/blast/matrices/
%   $Revision: 1.5 $ 

matrix = [...
    4  -4  -1  -1  -3  -2   0   0  -4  -2  -3  -3  -2  -5   0   1   1  -8  -5   0  -1  -1  -1 -10;...
   -4   7  -2  -5  -5   0  -4  -5   1  -3  -5   2  -2  -6  -1  -1  -3   0  -6  -4  -3  -1  -2 -10;...
   -1  -2   5   3  -6  -1   0  -1   2  -3  -4   1  -4  -5  -2   1   0  -5  -2  -4   4   0  -1 -10;...
   -1  -5   3   6  -8   0   4  -1  -1  -4  -7  -2  -5  -8  -4  -1  -2  -9  -6  -4   5   3  -2 -10;...
   -3  -5  -6  -8   9  -8  -8  -5  -5  -3  -9  -8  -8  -7  -5  -1  -4 -10  -1  -3  -7  -8  -5 -10;...
   -2   0  -1   0  -8   6   2  -3   2  -4  -3  -1  -2  -7  -1  -2  -3  -7  -6  -4   0   5  -2 -10;...
    0  -4   0   4  -8   2   6  -1  -1  -3  -5  -2  -4  -8  -2  -2  -2 -10  -6  -3   2   5  -2 -10;...
    0  -5  -1  -1  -5  -3  -1   5  -5  -5  -6  -4  -5  -6  -3   0  -2  -9  -8  -3  -1  -2  -2 -10;...
   -4   1   2  -1  -5   2  -1  -5   8  -5  -3  -2  -5  -3  -2  -3  -3  -4  -1  -4   1   1  -2 -10;...
   -2  -3  -3  -4  -3  -4  -3  -5  -5   6   1  -3   1   0  -4  -3   0  -8  -3   3  -3  -3  -2 -10;...
   -3  -5  -4  -7  -9  -3  -5  -6  -3   1   6  -5   2   0  -4  -5  -3  -3  -3   0  -5  -4  -3 -10;...
   -3   2   1  -2  -8  -1  -2  -4  -2  -3  -5   5   0  -8  -3  -1  -1  -6  -6  -5   0  -1  -2 -10;...
   -2  -2  -4  -5  -8  -2  -4  -5  -5   1   2   0   9  -1  -4  -3  -2  -7  -6   1  -5  -3  -2 -10;...
   -5  -6  -5  -8  -7  -7  -8  -6  -3   0   0  -8  -1   8  -6  -4  -5  -2   4  -4  -6  -8  -4 -10;...
    0  -1  -2  -4  -5  -1  -2  -3  -2  -4  -4  -3  -4  -6   7   0  -1  -8  -8  -3  -3  -2  -2 -10;...
    1  -1   1  -1  -1  -2  -2   0  -3  -3  -5  -1  -3  -4   0   4   2  -3  -4  -3   0  -2  -1 -10;...
    1  -3   0  -2  -4  -3  -2  -2  -3   0  -3  -1  -2  -5  -1   2   5  -7  -4  -1  -1  -2  -1 -10;...
   -8   0  -5  -9 -10  -7 -10  -9  -4  -8  -3  -6  -7  -2  -8  -3  -7  13  -2  -9  -7  -8  -6 -10;...
   -5  -6  -2  -6  -1  -6  -6  -8  -1  -3  -3  -6  -6   4  -8  -4  -4  -2   9  -4  -4  -6  -4 -10;...
    0  -4  -4  -4  -3  -4  -3  -3  -4   3   0  -5   1  -4  -3  -3  -1  -9  -4   6  -4  -3  -2 -10;...
   -1  -3   4   5  -7   0   2  -1   1  -3  -5   0  -5  -6  -3   0  -1  -7  -4  -4   4   2  -2 -10;...
   -1  -1   0   3  -8   5   5  -2   1  -3  -4  -1  -3  -8  -2  -2  -2  -8  -6  -3   2   5  -2 -10;...
   -1  -2  -1  -2  -5  -2  -2  -2  -2  -2  -3  -2  -2  -4  -2  -1  -1  -6  -4  -2  -2  -2  -2 -10;...
  -10 -10 -10 -10 -10 -10 -10 -10 -10 -10 -10 -10 -10 -10 -10 -10 -10 -10 -10 -10 -10 -10 -10   1;...
    ];

if nargout >1
    matrixInfo.Name = 'PAM90';
    matrixInfo.Scale = 1/2;
    matrixInfo.Entropy = 1.30 ;
    matrixInfo.ExpectedScore = -2.26;
    matrixInfo.LowestScore = -10;
    matrixInfo.HighestScore = 13;
    matrixInfo.Order = 'ARNDCQEGHILKMFPSTWYVBZX*';
end