get_formulas {enmpa}

Get GLM formulas according to defined response types

Description

Generate GLM formulas for independent variables predicting a dependent variable, taking into account response types required. All possible combinations of variables can be created using arguments of the function.

Usage

get_formulas(dependent, independent, type = "l", mode = "moderate",
             minvar = 1, maxvar = NULL)

get_formulas_main(dependent, independent, type = "l",
                  complex = FALSE, minvar = 1, maxvar = NULL)

aux_var_comb(var_names, minvar = 2, maxvar = NULL)

aux_string_comb(string)

Arguments

dependent

(character) name of dependent variable.

independent

(character) vector of name(s) of independent variable(s).

type

(character) a character string that must contain "l", "p", "q" or a combination of them. l = lineal, q = quadratic, p = interaction between two variables. Default = "l".

mode

(character) (character) a character string to indicate the strategy to create the formulas for candidate models. Options are: "light", "moderate", "intensive", or "complex". Default = "moderate".

minvar

(numeric) minimum number of independent variables in formulas.

maxvar

(numeric) maximum number of independent variables in formulas.

complex

(logical) whether to return the most complex formula.

var_names

sames as independent.

string

same as type.

Details

mode options determine what strategy to iterate the predictors defined in type for creating models:

• light.– returns simple iterations of complex formulas.

• moderate.– returns a comprehensive number of iterations.

• intensive.– returns all possible combination. Very time-consuming for 6 or more independent variables.

• complex.– returns only the most complex formula.

Value

A character vector containing the resulting formula(s).

Examples

# example variables
dep <- "sp"
ind <- c("temp", "rain", "slope")

# The most complex formula according to "type"
get_formulas(dep, ind, type = "lqp", mode = "complex")

# mode = 'light', combinations according to type
get_formulas(dep, ind, type = "lqp", mode = "light")

# mode = 'light', combinations according to type
get_formulas(dep, ind, type = "lqp", mode = "intensive")