ITWIST

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ITWIST=0 : the orientation of the homoclinic orbit is not computed.

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ITWIST=1 : the orientation of the homoclinic orbit is computed. For this purpose, the adjoint variational equation is solved for the unique bounded solution. If IRS = 0, an initial solution to the adjoint equation must be specified as well. However, if IRS>0 and ITWIST has just been increased from zero, then AUTO will automatically generate the initial solution to the adjoint. In this case, a dummy Newton-step should be performed, see Section 20.7 for more details.