function [CS] = CIR_to_CS(CIR,a,b,c)
    
% a,b,c is boundary to make decision of CS that is used
%     CS <= a    use CS1 ==> output = 1
% a < CS <= b    use CS2 ==> output = 2
% b < CS <= c    use CS3 ==> output = 3
%     CS >  c    use CS4 ==> output = 4


    CS=CIR;
    index=find(CS<=a);
    CS(index)=1;
    
    index=find(CS>a&CS<=b);
    CS(index)=2;
    
    index=find(CS>b&CS<=c);
    CS(index)=3;
    
    index=find(CS>c);
    CS(index)=4;