QBD_ParsePara.m

function QBD_ParsePara(A0,A1,A2)
%QBD_ParsePara checks the validity of the input matrices A0, A1 and A2
 
% check numeric 
if (~isnumeric(A0))
    error('MATLAB:QBD_ParsePara:InvalidInput',...
        'A0 has to be numeric');
end    
if (~isnumeric(A1))
    error('MATLAB:QBD_ParsePara:InvalidInput',...
        'A1 has to be numeric');
end    
if (~isnumeric(A2))
    error('MATLAB:QBD_ParsePara:InvalidInput',...
        'A2 has to be numeric');
end    
 
% check real
if (~isreal(A0))
    error('MATLAB:QBD_ParsePara:InvalidInput',...
        'A0 has to be a real matrix');
end    
if (~isreal(A1))
    error('MATLAB:QBD_ParsePara:InvalidInput',...
        'A1 has to be a real matrix');
end    
if (~isreal(A2))
    error('MATLAB:QBD_ParsePara:InvalidInput',...
        'A2 has to be a real matrix');
end    
 
% check dimension
if (size(A0,1) ~= size(A0,2))
    error('MATLAB:QBD_ParsePara:InvalidInput',...
        'A0 is not a square matrix');
end   
if (size(A1,1) ~= size(A1,2))
    error('MATLAB:QBD_ParsePara:InvalidInput',...
        'A1 is not a square matrix');
end   
if (size(A2,1) ~= size(A2,2))
    error('MATLAB:QBD_ParsePara:InvalidInput',...
        'A2 is not a square matrix');
end   
if (size(A0,1) ~= size(A1,1))
    error('MATLAB:QBD_ParsePara:InvalidInput',...
        'The matrices A0 and A1 do not have the same dimension');
end   
if (size(A0,1) ~= size(A2,1))
    error('MATLAB:QBD_ParsePara:InvalidInput',...
        'The matrices A0 and A2 do not have the same dimension');
end   
 
% check nonnegativity
if (min(min(A0)) < -10^(-14))
    error('MATLAB:QBD_ParsePara:InvalidInput',...
        'The matrix A0 contains negative data');
end    
if (min(min(A1)) < -10^(-14))
    error('MATLAB:QBD_ParsePara:InvalidInput',...
        'The matrix A1 contains negative data');
end    
if (min(min(A2)) < -10^(-14))
    error('MATLAB:QBD_ParsePara:InvalidInput',...
        'The matrix A2 contains negative data');
end    
 
% check (sub)stochasticity
if (max(sum(A0+A1+A2,2)) > 1+10^(-14))
    error('MATLAB:QBD_ParsePara:InvalidInput',...
        'The matrix A0+A1+A2 has to be (sub)stochastic');
end