Two-way Interaction Plot

The function creates a three-way interaction plot. By default, it will create an interaction plot with -1 SD and +1 SD of the two continuous variables, or the two levels of the binary variables or dummy-coded multi-categorical variable It has been superseded by interaction_plot.

two_way_interaction_plot(
  model,
  interaction_term = NULL,
  response_var_name = NULL,
  predict_var1_name = NULL,
  predict_var2_name = NULL,
  predict_var1_level = NULL,
  predict_var2_level = NULL,
  predict_var1_level_name = NULL,
  predict_var2_level_name = NULL,
  y_lim = NULL,
  plot_color = FALSE,
  return_plot_data = FALSE,
  return_plot = FALSE,
  verbose = FALSE,
  print_plot = TRUE,
  data = NULL
)

Arguments

model

a regression model object from effect.

interaction_term

default is the first interaction term in the model. The term should be given explicitly if you want to plot other interaction terms.

response_var_name

The name of the response variable can be changed using this value.

predict_var1_name

The name of the first predictor can be changed using this value.

predict_var2_name

The name of the second predictor can be changed using this value.

predict_var1_level

default is the -1 SD and +1 SD for continuous variable. They can be changed using this value.

predict_var2_level

default is the -1 SD and +1 SD for continuous variable. They can be changed using this value.

predict_var1_level_name

The labels of the level can be change using this value (e.g., c('-1 SD','+1 SD')). The order should be from the left to right on the x-axis.

predict_var2_level_name

The labels of the level can be change using this value (e.g., c('-1 SD','+1 SD')). The order should be from the top to down on the legend.

y_lim

the plot's upper and lower limit for the y-axis. Length of 2. Example: c(lower_limit, upper_limit)

plot_color

default if FALSE. Set to TRUE if you want to plot in color

return_plot_data

default is FALSE. Set to TRUE to return the plot data.

return_plot

default is FALSE. Set to TRUE to return the plot.

verbose

deafult is TRUE.

print_plot

default is TRUE. Set to TRUE to print the plot.

data

Optional data.frame. Only used when it is not possible to extract data from the model object.

Value

an object of class ggplot

Details

It appears that ``predict` cannot handle categorical factors. All variables are converted to numeric before plotting.