find_sigmoid_inflection_point

pymc_marketing.mmm.utils.find_sigmoid_inflection_point(alpha, lam)

Find the inflection point of the extended sigmoid function.

The inflection point of a function is the point where the function changes its curvature, i.e., it changes from being concave up to concave down, or vice versa. For the sigmoid function, this is the point where the function has its maximum rate of growth.

Parameters:

• alpha (float) – The asymptotic maximum or ceiling value of the sigmoid function.

• lam (float) – The parameter that affects how quickly the function approaches its upper and lower asymptotes.

Returns:

The x and y coordinates of the inflection point.

Return type:

tuple