---
title: "BRM on the house dataset (regression)"
output: rmarkdown::html_vignette
vignette: >
  %\VignetteIndexEntry{BRM on the house dataset (regression)}
  %\VignetteEngine{knitr::rmarkdown}
  %\VignetteEncoding{UTF-8}
---

```{r setup, include = FALSE}
knitr::opts_chunk$set(collapse = TRUE, comment = "#>")
set.seed(1234)
```

## Overview

A third regression demonstration on the King County house-sales dataset
(~21,600 rows), shipped in full with the package.

```{r load}
library(blockwise)
data(house)
str(house)
```

## Induce missingness, split, fit

```{r pipeline}
house_miss <- simulate_blockwise_missing(
  house,
  blocks = list(
    c("sqft_living", "sqft_lot", "sqft_above"),
    c("bedrooms", "bathrooms", "floors", "grade")
  ),
  prop_missing = 0.30,
  noise        = 0.05
)

set.seed(1234)
idx <- sample(nrow(house_miss), floor(0.75 * nrow(house_miss)))
train <- house_miss[idx, ]
test  <- house_miss[-idx, ]

X_train <- train[, setdiff(names(train), "price")]
y_train <- train$price
X_test  <- test[,  setdiff(names(test),  "price")]
y_test  <- test$price

set.seed(1234)
fit <- brm(X_train, y_train, learner = learner_lm())
fit

pred <- predict(fit, X_test)
cat("RMSE:", round(sqrt(mean((y_test - pred)^2)), 0), "\n")
```

## Citation

Srinivasan, K., Currim, F., and Ram, S. (2025). *A Reduced Modeling Approach
for Making Predictions With Incomplete Data Having Blockwise Missing
Patterns.* INFORMS Journal on Data Science.