function y=dengdaishijian(u,t)
[m n]=size(u);

for i=1:n
    x=u(i);
    if x<=
        y(i)=3*x-3*x^2/t-3*x^2+4*x^3/t;
    elseif x<=t
        y(i)=t/2+x+x^2-x^2/t-t*x;
    elseif x<=0.5
        y(i)=(2*t^2*x+6*x+6*t*x-12*x^2-6*t*x^2+8*x^3-t^2-3*t)/(2-2*t);
    elseif x<=(0.5+t/2)
        y(i)=(1-2*t-t^2+2*t*x-2*t*x^2+2*t^2*x)/(2-2*t);
    else 
        y(i)=(2+6*t*x^2-6*t*x+12*x^2-6*x-8*x^3)/(2-2*t);
    end
end