# pde4bvp.ode
#
# boundary value problem
# 0 = - (u_xxxx/pi^4+au_xx/pi^2)-u+r tanh(u)
# u,u_xx = 0 at x=0,1
u'=up
up'=upp
upp'=uppp
uppp'=pi^4*(r*tanh(u)-u-a*upp/(pi*pi))
par r=1,a=2
@ total=1.01,xhi=1,meth=cvode,bound=1000
@ dsmax=2,parmax=20,autoxmin=0,autoxmax=20,autoymin=-1,autoymax=4
b u
b u'
b upp
b upp'
done