assert_monotonic

pymc_marketing.mmm.lift_test.assert_monotonic(delta_x, delta_y)

Check if the lift test results satisfy the increasing assumption.

The increasing assumption states that if delta_x is positive, delta_y must be positive, and vice versa.

Parameters:

delta_xpd.Series

Series with the change in x axis value of the lift test.

delta_ypd.Series

Series with the change in y axis value of the lift test.

Raises:

NonMonotonicError

If the lift test results do not satisfy the increasing assumption.