how to find alpha plot in r which is the first order of the arima plot in r arima model pcf plots what is pcf plot what is the plot of the arima model what is acf plots what is the purpose of acf in arima model acf/pacf in arima what is apcf plots what is apcf of arima acf plot arima what is acf and pcf what is the difference between acf and pacf in arima what type of function does arcima have how to plot in arima model arcf pacf how to generate acf and pacf plots in r what is pcf in r which r function is used to generate apcf plots? what is the acf of the arima model?