#
#  Nice Polar Problems 
#
#  Parameter default values
#
p mu=1
#
#  Vector field definition
#
h(z)=mu-z
f(x,y)=-y+x*h(sqrt(x^2+y^2))
g(x,y)=x+y*h(sqrt(x^2+y^2))
#
#  ODE definition
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x'=f(x,y)
y'=g(x,y)
#
aux r=sqrt(x^2+y^2)
#
#  Program parameters (optional)
#
@ total=20, xlo=-3,xhi=3,ylo=-3,yhi=3
@ maxstor=2000000
@ nplot=1,xpt=x,yp1=y
@ BUT=DynamicsRocks:fq