By default, a kpss test (via feasts::unitroot_kpss()) will be performed for testing the required first order differences, and a test of the seasonal strength (via feasts::feat_stl() seasonal_strength) being above the 0.64 threshold is used for determining seasonal required differences.

unitroot_options(
ndiffs_alpha = 0.05,
nsdiffs_alpha = 0.05,
ndiffs_pvalue = ~feasts::unitroot_kpss(.)["kpss_pvalue"],
nsdiffs_pvalue = ur_seasonal_strength(0.64)
)

## Arguments

ndiffs_alpha, nsdiffs_alpha The level for the test specified in the pval functions. As long as pval < alpha, differences will be added. A function (or lambda expression) that provides a p-value for the unit root test. As long as pval < alpha, differences will be added. For the function for the seasonal p-value, the seasonal period will be provided as the .period argument to this function. A vector of data to test is available as . or .x.

## Value

A list of parameters