%Script to plot Normal(x/sqrt(2*t)).  (Normal refers to the 
%standard normal distrivution function.)  The script assumes
%a value N for the number of plot points to be predefined.
x=linspace(-1,1,2*N+1); t=linspace(0,1,N+1);
[X,T]=meshgrid(x,t);
U=erfc(-X./sqrt(2*T))/2; %erfc(+-Inf) is acceptable
surf(X,T,U)
xlabel('x'); ylabel('tau');zlabel('u');