#
# Solitons
# 
c1 = 1; c2 = 0.1;
set dummy x,t;

f(x,t) = c1 *  exp( c1 *x + c1^2 * t) / \
(1. + exp( c1 *x + c1^2 * t) + exp( c2 *x + c2^2 * t) );

a = sur{[8.0* f(x,t)][x=-10:10][t=-20:10]};
plot a;

