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Define a response form for a nonlinear model

hlpr_define_response_form.Rd

This function defines a response form for a nonlinear model based on the specified type. It uses the `brms` package to create a formula for the response variable.

Usage

hlpr_define_response_form(type, x = NULL, y = NULL)

Arguments

type

A character string specifying the type of response form. Valid options are "logistic", "log_logistic", "gompertz", "reflected_gompertz", "weibull", and "reflected_weibull".

x

A character string representing the name of the predictor variable.

y

A character string representing the name of the response variable.

Value

A `brms` formula object representing the response form.

Details

The function supports the following response forms:

  • logistic: \(y = c + ((d - c)/(1 + exp(b*(x - e))))\)

  • log_logistic: \(y = c + ((d - c)/(1 + exp(b*(log(x) - log(e))))\)

  • gompertz: \(y = c + (d - c) * exp(-exp(b * (x - e)))\)

  • reflected_gompertz: \(y = c + (d - c) * (1 - exp(-exp(b * (-x + e))))\)

  • weibull: \(y = c + (d - c) * exp(-exp(b * (log(x) - log(e))))\)

  • reflected_weibull: \(y = c + (d - c) * (1 - exp(-exp(b * (-log(x) + log(e))))\)