make_new_data: Make new data for generating predicted data from regression...

In jtools: Analysis and Presentation of Social Scientific Data

Make new data for generating predicted data from regression models.

Description

This is a convenience function that helps automate the process of generating predicted data from regression model from a predictor(s). It is designed to give you the data frame for the predict method's newdata argument.

Usage

make_new_data(
  model,
  pred,
  pred.values = NULL,
  at = NULL,
  data = NULL,
  center = TRUE,
  set.offset = NULL,
  num.preds = 100,
  ...
)

Arguments

model	The model (e.g., lm, glm, merMod, svyglm)
pred	The name of the focal predictor as a string. This is the variable for which, if you are plotting, you'd likely have along the x-axis (with the dependent variable as the y-axis).
pred.values	The values of pred you want to include. Default is NULL, which means a sequence of equi-spaced values over the range of a numeric predictor or each level of a non-numeric predictor.
at	If you want to manually set the values of other variables in the model, do so by providing a named list where the names are the variables and the list values are vectors of the values. This can be useful especially when you are exploring interactions or other conditional predictions.
data	The data frame used in fitting the model. Default is NULL, in which case the data will be retrieved via model.frame or, if there are variable transformations in the formula, by looking in the environment for the data.
center	Set numeric covariates to their mean? Default is TRUE. You may also just provide a vector of names (as strings) of covariates to center. Note that for svyglm models, the survey-weighted means are used. For models with weights, these are weighted means.
set.offset	If the model has an offset, the value to use for the offset variable. Default is NULL, in which case the median of the offset variable is used.
num.preds	The number of predictions to generate. Default is 100. Ignored if pred.values is not NULL.
...	Extra arguments passed to get_formula()

Details

Please bear in mind that this does not generate the predictions. You will need to do that with a predict function for your model or another interface, such as the prediction package's titular function.

Value

A data frame.

Examples

fit <- lm(Income ~ Frost + Illiteracy + Murder, data = as.data.frame(state.x77))
# Basic use
new_data <- make_new_data(fit, pred = "Frost")
# Set covariate to specific value
new_data <- make_new_data(fit, pred = "Frost", at = list(Murder = 5))
# Set covariate to several specific values
new_data <- make_new_data(fit, pred = "Frost", at = list(Murder = c(5, 10, 15)))

jtools documentation built on Sept. 11, 2024, 7 p.m.