---
title: "Mars Runtime Basics"
output: rmarkdown::html_vignette
vignette: >
  %\VignetteIndexEntry{Mars Runtime Basics}
  %\VignetteEngine{knitr::rmarkdown}
  %\VignetteEncoding{UTF-8}
---

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

## Overview

`marsearth` provides a portable R surface for validated Mars `ModelSpec`
artifacts. It can validate, replay, and inspect portable artifacts through the
same package interface that the release docs and package manual describe.

## Loading a model specification

```{r}
library(marsearth)

spec <- list(
  spec_version = "1.0",
  basis_terms = list(list(kind = "constant")),
  coefficients = list(1),
  feature_schema = list(n_features = 0)
)

validate_model_spec(spec)
```

## Replaying predictions

```{r}
rows <- matrix(numeric(0), nrow = 1, ncol = 0)
design_matrix(spec, rows)
predict_model(spec, rows)
```

## Training

When the Rust runtime helper is available, `fit_model()` can fit a portable
specification from feature and response data. The actual training path is
runtime-dependent, so this vignette shows the call without executing it.

```{r, eval=FALSE}
fit_model(
  x = matrix(c(0, 1, 2), ncol = 1),
  y = c(1, 3, 5),
  max_terms = 5,
  max_degree = 1,
  penalty = 3.0
)
```

## Validation

For source-tree validation, run:

```sh
Rscript tests/conformance.R
Rscript tests/training.R
```

For package publication validation, run:

```sh
R CMD build .
R CMD check --no-manual --as-cran marsearth_*.tar.gz
R CMD Rd2pdf .
```
