plot.unitquantregs: Plot method for `unitquantregs` objects

Description

Provide two type of plots for unitquantregs objects.

Usage

# S3 method for unitquantregs
plot(
  x,
  which = c("coef", "conddist"),
  output_df = FALSE,
  parm = NULL,
  level = 0.95,
  mean_effect = FALSE,
  mfrow = NULL,
  mar = NULL,
  ylim = NULL,
  main = NULL,
  col = gray(c(0, 0.75)),
  border = NULL,
  cex = 1,
  pch = 20,
  type = "b",
  xlab = bquote("Quantile level (" * tau * ")"),
  ylab = "Estimate effect",
  dist_type = c("density", "cdf"),
  at_avg = TRUE,
  at_obs = NULL,
  legend_position = "topleft",
  ...
)

Value

If output_df = TRUE then returns a data.frame used to plot. Otherwise, no return value, called for side effects.

Arguments

x: fitted model object of class unitquantregs.
which: character. Indicate the type of plot. Currently supported are "coef" which provide the estimated coefficients for several quantiles and "conddist" which provide the conditional distribution (cdf or pdf) at specific values of covariates.
output_df: logical. Should data.frame used to plot be returned?
parm: a specification of which parameters are to be plotted, either a vector of numbers or a vector of names. By default, all parameters are considered.
level: level of significance for the confidence interval of parameters.
mean_effect: logical. Should a line for the mean effect coefficients be added?
mfrow, mar, ylim, main, col, border, cex, pch, type, xlab, ylab: graphical parameters.
dist_type: character. Which conditional distribution should be plotted? The options are "density" or "cdf".
at_avg: logical. Should consider the conditional distribution at average values of covariates?
at_obs: list. List with name and values for each covariate.
legend_position: character. The legend position argument used in legend function.
...: other parameters to be passed through to plotting functions.

Author

André F. B. Menezes

Details

The plot method for unitquantregs objects is inspired in PROC QUANTREG of SAS/STAT. This plot method provide two type of visualizations.

If which = "coef" plot the estimated coefficients for several quantiles.