It has the same function of Buildchar, but, it shuffles the characters states n times to build the nexus file used for modified PTP text (1 and 2).
If you have an slow compute, it may take a while to open the file generated by Buildptp.
1. Wahlberg N: The phylogenetics and biochemistry of host-plant specialization in Melitaeine butterflies (Lepidoptera: Nymphalidae). Evolution 2001, 55:522-537.
2. Faith DP, Cranston PS: Could a cladogram this short have arisen by chance alone?: On permutation tests for cladistic structure. Cladistics 1991, 5:235-258.