| bgnbd_pmf {CLVTools} | R Documentation | 
BG/NBD: Probability Mass Function (PMF)
Description
Calculate P(X(t)=x), the probability that a randomly selected customer makes exactly x transactions in the interval (0, t].
Usage
bgnbd_nocov_PMF(r, alpha, a, b, x, vT_i)
bgnbd_staticcov_PMF(r, x, vAlpha_i, vA_i, vB_i, vT_i)
Arguments
| r | shape parameter of the Gamma distribution of the purchase process | 
| alpha | scale parameter of the Gamma distribution of the purchase process | 
| a | shape parameter of the Beta distribution of the lifetime process | 
| b | shape parameter of the Beta distribution of the lifetime process | 
| x | The number of transactions to calculate the probability for (unsigned integer). | 
| vT_i | Number of periods since the customer came alive. | 
| vAlpha_i | Vector of individual parameters alpha | 
| vA_i | Vector of individual parameters a | 
| vB_i | Vector of individual parameters b | 
Value
Returns a vector of probabilities.
References
Fader PS, Hardie BGS, Lee KL (2005). ““Counting Your Customers” the Easy Way: An Alternative to the Pareto/NBD Model” Marketing Science, 24(2), 275-284.
Fader PS, Hardie BGS (2013). “Overcoming the BG/NBD Model's #NUM! Error Problem” URL http://brucehardie.com/notes/027/bgnbd_num_error.pdf.
Fader PS, Hardie BGS (2007). “Incorporating time-invariant covariates into the Pareto/NBD and BG/NBD models.” URL http://www.brucehardie.com/notes/019/time_invariant_covariates.pdf.
Fader PS, Hardie BGS, Lee KL (2007). “Creating a Fit Histogram for the BG/NBD Model” URL https://www.brucehardie.com/notes/014/bgnbd_fit_histogram.pdf