14. The method of claim 13 , wherein adjusting the write clock frequency includes providing a first write clock frequency for a first portion of the data medium and a second write clock frequency for a second portion of the data medium.
14. The method of claim 13 , wherein adjusting the write clock frequency includes providing a first write clock frequency for a first portion of the data medium and a second write clock frequency for a second portion of the data medium. 16. The method of claim 14 , wherein the data medium is a bit patterned media and wherein adjusting a write clock frequency includes compensating for the difference between the write clock frequency and a bit island frequency.