## ----setup, include = FALSE---------------------------------------------------
knitr::opts_chunk$set(
  echo = TRUE, message = FALSE, warning = FALSE,
  collapse = TRUE, comment = "#>"
)

## ----setup-data, eval = FALSE-------------------------------------------------
# library(gdpar)
# set.seed(2026L)
# n <- 300L
# 
# df <- data.frame(x1 = rnorm(2L * n))
# df$arm <- rep(c("treat", "ctrl"), each = n)
# df$y <- with(df, ifelse(arm == "treat", 0.5, 0) +
#                  0.8 * x1 +
#                  rnorm(2L * n, sd = 0.5))
# df_t <- subset(df, arm == "treat"); df_t$arm <- NULL
# df_c <- subset(df, arm == "ctrl");  df_c$arm <- NULL
# 
# fit_t <- gdpar(y ~ x1, amm = amm_spec(a = ~ x1), data = df_t,
#                iter_warmup = 300, iter_sampling = 300, chains = 2)
# fit_c <- gdpar(y ~ x1, amm = amm_spec(a = ~ x1), data = df_c,
#                iter_warmup = 300, iter_sampling = 300, chains = 2)
# 
# newdata <- data.frame(x1 = seq(-2, 2, length.out = 21L))
# bridge <- gdpar_causal_bridge(fit_t, fit_c, newdata = newdata)

## ----grf-quick, eval = FALSE--------------------------------------------------
# adapter_grf <- gdpar_adapter_grf(num_trees = 500L, seed = 2026L)
# cmp <- gdpar_compare_meta_learners(
#   bridge,
#   methods = list(grf = adapter_grf)
# )
# print(cmp)
# summary(cmp)

## ----grf-predict, eval = FALSE------------------------------------------------
# newdata2 <- data.frame(x1 = seq(-1.5, 1.5, length.out = 15L))
# cmp_new  <- predict(cmp, newdata = newdata2)

## ----econml-install, eval = FALSE---------------------------------------------
# # 1. Install reticulate (R-side) if absent.
# install.packages("reticulate")
# 
# # 2. Register econml as a Python requirement, then install it.
# reticulate::py_require("econml")  # reticulate 1.46+ ephemeral-env style
# reticulate::py_install("econml")  # adds econml to the active env
# 
# # 3. Verify.
# reticulate::py_module_available("econml")  # should be TRUE

## ----econml-use, eval = FALSE-------------------------------------------------
# adapter_econml <- gdpar_adapter_econml(n_estimators = 500L, seed = 2026L)
# cmp2 <- gdpar_compare_meta_learners(
#   bridge,
#   methods = list(grf    = adapter_grf,
#                  econml = adapter_econml)
# )
# print(cmp2)
# summary(cmp2)

## ----doubleml-sketch, eval = FALSE--------------------------------------------
# fit_predict_dml <- function(X, Y, T, X_newdata, level, seed_run) {
#   if (!requireNamespace("DoubleML", quietly = TRUE) ||
#       !requireNamespace("mlr3learners", quietly = TRUE)) {
#     stop("DoubleML and mlr3learners are required for this adapter.")
#   }
#   d <- cbind(X, Y = as.numeric(Y), T = as.integer(T))
#   dml_data <- DoubleML::DoubleMLData$new(d, y_col = "Y", d_cols = "T",
#                                           x_cols = setdiff(colnames(d),
#                                                             c("Y", "T")))
#   learner_g <- mlr3::lrn("regr.ranger", num.trees = 200L)
#   learner_m <- mlr3::lrn("classif.ranger", num.trees = 200L,
#                           predict_type = "prob")
#   model <- DoubleML::DoubleMLPLR$new(dml_data, ml_g = learner_g$clone(),
#                                       ml_m = learner_m$clone())
#   model$fit()
#   est <- as.numeric(model$coef)
#   est_se <- as.numeric(model$se)
#   z <- stats::qnorm(1 - (1 - level) / 2)
#   n_new <- nrow(X_newdata)
#   list(
#     cate_mean = rep(est, n_new),
#     cate_ci   = cbind(lower = rep(est - z * est_se, n_new),
#                        upper = rep(est + z * est_se, n_new)),
#     state     = list(model = model),
#     notes     = "DoubleMLPLR returns a single ATE coefficient; broadcast to a constant CATE."
#   )
# }
# 
# predict_dml <- function(state, X_newdata, level) {
#   n_new <- nrow(X_newdata)
#   est <- as.numeric(state$model$coef)
#   est_se <- as.numeric(state$model$se)
#   z <- stats::qnorm(1 - (1 - level) / 2)
#   list(
#     cate_mean = rep(est, n_new),
#     cate_ci   = cbind(lower = rep(est - z * est_se, n_new),
#                        upper = rep(est + z * est_se, n_new))
#   )
# }
# 
# adapter_dml <- gdpar_meta_learner_adapter(
#   name = "doubleml_plr",
#   fit_predict_fun = fit_predict_dml,
#   predict_fun = predict_dml,
#   requires_r = c("DoubleML", "mlr3", "mlr3learners"),
#   native_ci = TRUE,
#   description = "DoubleMLPLR (constant CATE; useful as a robust ATE benchmark)"
# )
# 
# cmp_with_dml <- gdpar_compare_meta_learners(
#   bridge,
#   methods = list(grf = adapter_grf, dml = adapter_dml)
# )