Restrictions on the Use of PAR.

The parameters PAR(1) - PAR(9) can be used freely by the user. The other parameters are used as follows :

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PAR(11) : The value of PAR(11) equals the length of the time interval over which a homoclinic solution is computed. Also referred to as ``period''. This must be specified in STPNT.

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PAR(10) : If ITWIST=1 then PAR(10) is used internally as a dummy parameter so that the adjoint equation is well-posed.

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PAR(12)-PAR(20) : These are used for specifying the equilibria and (if ISTART=3) the artificial parameters of the homotopy method (see Section 20.7 below).

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PAR(21)-PAR(36) : These parameters are used for storing the test functions (see Section 20.6).

The output is in an identical format to AUTO except that additional information at each computed point is written in fort.9. This information comprises the eigenvalues of the (left-hand) equilibrium, the values of each activated test function and, if ITWIST=1, whether the saddle homoclinic loop is orientable or not. Note that the statement about orientability is only meaningful if the leading eigenvalues are not complex and the homoclinic solution is not in a flip configuration, that is, none of the test functions $\psi_i$ for $i=11,12,13,14$ is zero (or close to zero), see Section 20.6. Finally, the values of the NPSI activated test functions are written.