Methods for fitting point processes with parameters of generalised additive
model (GAM) form are provided. For an introduction to point processes see Cox, D.R &
Isham, V. (Point Processes, 1980, CRC Press), GAMs see Wood, S.N. (2017)
, and the fitting approach see Wood, S.N., Pya, N. &
Safken, B. (2016) .