The evaluated value Smn=Mm× is calculated from {TAIL ~ a plurality} of {HEAD ~ different write power compensated values Pcn} , the write power Pwm, and the modulation Mm 
The evaluated value Smn = Mm× is calculated from { TAIL ~ a plurality } of { HEAD ~ different write power compensated values Pcn } , the write power Pwm , and the modulation Mm
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH