public:static double fn(double T,double x)
           {
               if (x>=0)
                   return T;
               else if(x<0)
                   return 0;
           }

public: void drawfunc(double T)
            {
                double xmin = -5;
                double xmax = 10;
                for(double x = xmin;x<xmax;x+=0.01)
                {
                    chart1->Series["Series1"]->Points->AddXY(x,fn(T,x));
                }
            }

public:void draw(double U,double T)
       {
           double xmin=-5;
           double xmax=10;
           for(double x=xmin;x<xmax;x+=0.01)
               chart1->Series["Line"]->Points->AddXY(x,heviside(T));
       }