### Fold of cycles initialization

One way to start a Fold bifurcation of cycles continuation supported in the current version is to start it from a fold bifurcation point (LPC) on a limit cycle curve. This can be done using the following command: `[x0,v0]=init_LPC_LPC(@odefile, x, s, ap, ntst, ncol )`. `x` should be the `x` as returned by the previous limit cycle continuation. `s` is the special point structure of the detected Fold bifurcation point on the limit cycle curve. `odefile` specifies the ode-file to be used. `ap` is the active parameter and `ntst` and `ncol` are again the number of mesh and collocation points for the discretization. `bp` are the optional indices of the branch parameters. It also works without entering a value for this field: `[x0,v0]=init_LPC_LPC(@odefile, x, s, ap, ntst, ncol)`.

MATCONT provides four other initializers which allow to start a continuation of folds of limit cycles by starting from an codim2 bifurcation of limit cycles. These are `init_CPC_LPC.m,` `init_LPNS_LPC.m,` `init_LPPD_LPC.m` and `init_R1_LPC.m`. These initializers are introduced for ease of use since they refer back to `init_LPC_LPC.m`.

A more interesting and indeed nontrivial initializer is `init_GH_LPC.m`. Computational methods to switch to nonhyperbolic cycles from codim 2 bifurcations of equilibria are discussed in [29].