price2ret(TickSeries,TickTimes,Method),method为空或者为 'Continuous'  注意大小写

那个TickSeries
TickTimes
是什么参数呢？

TickTimes       

A NUMOBS element vector of monotonically increasing observation times. Times are numeric and taken either as serial date numbers (day units), or as decimal numbers in arbitrary units (for example, yearly). If TickTimes is [] or unspecified, then price2ret assumes sequential observation times from 1, 2, ..., NUMOBS.

此项可空

收益率不是y（t）=ln(x(t)/x(t-1)）么

最简单的办法。。 logreturn=diff(log(close))