function x = g_t(t,k,a)
           %STAT Interesting statistics.
           x1 = rectpuls(k*t+a-0.5,1);
           x2 = -k*2*t-a+2;
           x3 = rectpuls(k*t+a-1.25,0.5);
          
           x = x1  + x2.*x3;
           
 end