function [valor,a,b,c,d] = Spline(vy,vx,xinter)
    a=vy;
    valor=0;
    c=0;b=0;d=0;
    h=0;A=eye(length(vx));B=zeros([length(vx)],1);
    for i=1:(length(vx)-1)
        h(i)=vx(i+1)-vx(i);
    end
    for i=2:length(h)
        A(i,i)=2*(h(i)+h(i-1));
        A(i,i-1)=h(i-1);
        A(i,i+1)=h(i);
        B(i,1)=((3/h(i))*(a(i+1)-a(i)))-((3/h(i-1))*(a(i)-a(i-1)));
    end
    c=inv(A)*B;
    c=c';
    for(i=1:length(h))
        b(i)=((a(i+1)-a(i))/h(i))-((h(i)/3)*(c(i+1)+2*c(i)));
    end
    for(i=1:length(h))
        d(i)=(c(i+1)-c(i))/(3*h(i));
    end
   
    for(i=1:length(vx)-1)
        if(vx(i)<=xinter)
            if(xinter<=vx(i+1))
                valor=a(i)+b(i)*(xinter-vx(i))+c(i)*(xinter-vx(i))^2+d(i)*(xinter-vx(i))^3;
            end
        end
    end
    disp(valor)
end