用R auto.arima 算出 Best model: ARIMA(0,0,1)

用R auto.arima 算出 Best model: ARIMA(0,0,1) with non-zero mean 结果如下： Series: tsdata ARIMA(0,0,1) with non-zero mean Coefficients: ma1 mean 0.5687 66.7034 s.e. 0.1099 3.4399 sigma^2 estimated as 302: log likelihood=-255.63 AIC=517.26 AICc=517.69 BIC=523.54 1.这个with non-zero mean 是什么意思呢？ 2.m1.tsdata=arima(tsdata,order=c(0,0,1)) 这么写对么？