function Y = zhuanhuan(X)
switch X
    case 0
        Y=0000;
    case 1
        Y=0001;
    case 2
        Y=0010;
    case 3
        Y=0011;
    case 4
        Y=0100;
    case 5
        Y=0101;
    case 6
        Y=0110;
    case 7
        Y=0111;
    case 8
        Y=1000;
    case 9
        Y=1001;
    case 10
        Y=1010;
    case 11
        Y=1011;
    case 12
        Y=1100;
    case 13
        Y=1101;
    case 14
        Y=1110; 
    otherwise
        Y=1111;
end