#-----------------------------------------------------
# Simple Soliton soln to the KdV eq.  
#
#
set title "Soliton Solution of the KdV Equation";
set dummy u,v;
c= 3.0/5.0;
f1(u,v) = exp(c*u - c^3 * v);
f2(u,v) = 1.0 + f1(u,v);
kdv(u,v) = 3*c^2 * f1(u,v) / (f2(u,v))^2;

soliton = sur{[15*kdv(u,v)][u=-10:10][v=-10:10]};
plot soliton;
set notitle;
set dummy x,y;
#-----------------------------------------------------