id_plot_irf: Generate Impulse Response Functions for Covariates

In idealstan: Generalized IRT Ideal Point Models with 'Stan'

Description

This function will generate an impulse response function (IRF) for a given covariate. The IRF shows the marginal impact of a 1-unit change in the covariate on a person's ideal point over time. To use this function, the vary_ideal_pts option in id_estimate must have received the 'AR1' option as IRFs are only available for the AR(1) auto-regressive model.

Usage

id_plot_irf(object, cov_name = NULL, label_high = "Liberal",
  label_low = "Conservative", pred_outcome = NULL, recalc_vals = F,
  include = NULL, time_calc = 10, time_label = "Time Points",
  line_type = 2, line_width = 1, line_alpha = 1,
  line_color = "red", ci_color = "black", ci_alpha = 0.5,
  use_ci = TRUE, high_quantile = 0.95, low_quantile = 0.05,
  calc_varying = T)

Arguments

object	A fitted idealstan object
cov_name	The name of the covariate to plot. Leave blank to select from a list of available covariates
label_high	The character label for the upper end of the latent scale
label_low	The character label for the lower end of the latent scale
pred_outcome	For discrete models with more than 2 categories, or binary models with missing data, which outcome to predict. This should be a character value that matches what the outcome was coded as in the data passed to id_make.
recalc_vals	Whether to combine two variables into one through addition before computing IRFs. If TRUE, two names of parameters should be passed to cov_name or selected from the dialog list
include	A list of character names of person or group IDs for which to calculate IRFs
time_calc	The maximum number of time points over which to calculate the IRF
time_label	Character string specifying the type of time points (default is just "Time Points")
line_type	The line type of the IRF line (see ggplot2 documentation)
line_width	The line width of the IRF line (see ggplot2 documentation)
line_alpha	The line alpha (transparency) of the IRF line (see ggplot2 documentation)
line_color	The color of the IRF line (see ggplot2 documentation)
ci_color	The color of the IRF credible interval (see ggplot2 documentation)
ci_alpha	The alpha of the IRF credible interval (see ggplot2 documentation)
use_ci	Whether or not to plot a credible interval around the lines
high_quantile	The upper limit of the posterior density to use for calculating credible intervals
low_quantile	The lower limit of the posterior density to use for calculating credible intervals
calc_varying	if TRUE, will calculate marginal effects of the covariates on each end of the latent scale (see vignette for more information)

Value

a ggplot2 object that can be further customized if necessary

idealstan documentation built on July 10, 2019, 5:05 p.m.