pgam.parser				Read the model formula and split it into two new ones:
						parametric and nonparametric partitions of predictor.
pgam.filter				Run appropriate recursions for estimation of priori and 
						posteriori conditional distribution parameters of the level.
pgam.likelihood			Likelihood function to be maximized.
pgam.fit				Estimate one-step ahead expectation of y_t conditional
						on Y_t-1.
pgam.psi2par			Put hyperparameters into unconstrained form for optimization.
pgam.par2psi			Put optimized parameters back into omega and beta form.
pgam.hes2se				Put hyperparameters hessian matrix in the form of omega and beta
						standard error.
pgam					Fit a Poisson-Gamma Additive Model (PGAM).
residuals.pgam			Method for residuals extraction.
predict.pgam			Method for k-step ahead forecasting.
fitted.pgam				Method for fitted values extraction.
coef.pgam				Method for parametric coefficients extraction. 
logLik.pgam				Method for loglik value extraction.
deviance.pgam			Method for deviance extraction.
AIC.pgam				Method for appproximate AIC estimation.
summary.pgam			Method for output model information.
print.summary.pgam		Method for summary printing.
plot.pgam				Method for level and smooth terms plotting.
f						Build seasonal factors data matrix.
g						Extract smoothing information from the formula.
fnz						Return first non-zero observation index.
framebuilder			Build a data frame given the formula.
backfitting				Fit the nonparametric partition of a PGAM moel.
pgam.smooth				Wrapper for the smoothers functions
elapsedtime				Compute the elapsed time between start and end time.
link					Aplly the link function or its inverse.
lpnorm					Return the Lp-norm. If p=0 then Infinity norm is returned.
intensity				Spectral decomposition of a time series.
periodogram				Create and plot the periodogram of a time series.
envelope				Simulate and plot an envelope of residuals of a PGAM model.
tbl2tex					Export a data frame to a fancy LaTeX table environment.
