function standard_R(R_array)
% Tells us whether R is standard 10% value

% Check for 2-digit integer valies.
% Compute diff between R values and ints
differ = R_array - floor(R_array);

if any(differ > 10*eps)
    display('Error: not a 2-digit R value')
    return
end

stand_R = [10, 11, 12, 15, 18, 20 ];  % There are more...

for index_R = 1:length(R_array)
    R = R_array(index_R);
    if R*ones(1,length(stand_R)) == any(stand_R)
        display('standard R value')
    else
        display('not standard R value')
    end
end

end

