foehnix Families

The foehnix mixture models are based on a set of families provided with this package. Currently, the package provides a two-component Gaussian and a two-component logistic mixture model and their truncated and censored versions.

The method foehnix allows to specify a family argument which has to be either "gaussian" (the default) or "logistic" at the moment. If finite arguments for left and/or right are set as well a censored Gaussian/logistic mixture model will be estimated (or truncated, if truncated = TRUE).

However, feel free to develop custom family objects if needed: if a foehnix.family object is provided on family when calling foehnix this custom object will be used. For example:

fam <- foehnix:::foehnix_cgaussian(left = 0)
mod <- foehnix(dt ~ ff + dd + rh, data = data, family = fam)

For all others the two family classes provided with the package should typically be more than suitable for foehn classification.

foehn.family Objects

Each foehn.family object consists of a set of functions:

• optional arguments not listed here (stored inside the object environment when specified on initialization, left and right used for the censored and truncated Gaussian/logistic families are such examples).
• name: character, name of the family object.
• d: density function of the mixture distribution.
• p: distribution function of the mixture distribution.
• r: not required for optimization but nice for testing: returns random numbers from the mixed distribution to simulate data.
• loglik: function returning the log-likelihood sum, used for model estimation (EM algorithm).
• posterior: returns the (updated) posterior probabilities, used for model estimation (EM algorithm).
• theta: returns the parameters of the distributions of the components of the mixture models. Used for model estimation (EM algorithm).

Examples are: foehnix_gaussian, foehnix_cgaussian, foehnix_tgaussian, foehnix_logistic, foehnix_clogistic, and foehnix_tlogistic in R/families.R.