time series analysis with r for arma

library(readxl)
library(forecast)
library(TSA)
library(lmtest)

mydata=read_excel("文档位置",sheet = 1)

tsdata <- ts(mydata)

diff1<-diff(tsdata)
plot(diff1,type="o")
diff2<-diff(tsdata2)
plot(diff2,type="o")

diff1<-diff(log(tsdata))
plot(diff1,type="o")
diff2<-diff(log(tsdata),2)
plot(diff2,type="o")

ndiffs(tsdata)

acf(tsdata)
pacf(tsdata)

eacf(tsdata)

auto.arima(tsdata)
sol <- stats::arima((tsdata,order=c(p,d,q))

forecast <- forecast.Arima(sol,h=50,level=c(99.5))
forecast
plot.forecast(forecast)

tsdiag(sol)