# Is adf.test is one of the ways to know whether the time series is stationary or not? [duplicate]

I have time series data. Not sure whether the series is stationary or not. I applied adf.test and got a p-value much higher than 0.05 which I think means that the data is not stationary. I took differencing once to check the p-value again. And I see that p-value has gone below 0.05. Can I assume that the data is stationary and ready for forecast? Is there any other way to confirm this in 'R'?

## marked as duplicate by Stephan Kolassa, Peter Flom♦Jul 14 '18 at 12:17

• Did you made a plot before to jump into computations ? – AlainD Jul 10 '18 at 18:32
• Yes.. plotted ACF and PACF as well, I could see autocorrelation in the data. Once I took differencing, I don't see autocorrelation and adf.test also shows p-value less than 0.05 – Vijaya Patil Jul 11 '18 at 17:11