---
title: "Custom value sets"
output: rmarkdown::html_vignette
vignette: >
  %\VignetteIndexEntry{Custom value sets}
  %\VignetteEngine{knitr::rmarkdown}
  %\VignetteEncoding{UTF-8}
---

```{r setup, include = FALSE}
knitr::opts_chunk$set(
  collapse = TRUE,
  comment  = "#>"
)
library(eq5dsuite)
```

## Introduction

New EQ-5D value sets are published regularly. Rather than
waiting for a package update, `eq5dsuite` allows you to
add your own value sets using `eqvs_add()`. Custom value
sets work with all scoring and analysis functions in the
package.

## Adding a custom value set

A custom value set must be a data frame with two columns:

- `state` — the EQ-5D health state code (integer)
- A column named after the VS_code containing utility values

```{r add-custom-vs}
# Generate all valid 3L health state codes
states <- make_all_EQ_indexes(version = "3L")

# Create a custom value set (random values for illustration)
set.seed(42)
custom_vs <- data.frame(
  state  = states,
  MY_VS  = runif(243, min = -0.5, max = 1.0)
)

head(custom_vs)
```

```{r register-vs, eval = FALSE}
# Register for current session only (saveOption = 1)
eqvs_add(
  custom_vs,
  version     = "3L",
  country     = "My Country",
  countryCode = "MC",
  VSCode      = "MY_VS",
  description = "Custom value set — demonstration",
  saveOption  = 1
)

# Verify it appears in the list
eqvs_display(version = "3L")

# Use it for value calculation
eq5d3l(c(11111, 12321), country = "MY_VS")
```

## Saving a custom value set permanently

To persist a custom value set across R sessions, use
`saveOption = 2`:

```{r save-vs, eval = FALSE}
eqvs_add(
  custom_vs,
  version     = "3L",
  country     = "My Country",
  countryCode = "MC",
  VSCode      = "MY_VS",
  description = "Custom value set — permanent",
  saveOption  = 2  # saves to user cache
)
```

Load it in a new session with:

```{r load-vs, eval = FALSE}
eqvs_load(country = "MY_VS", version = "3L")
```

## Removing a custom value set

```{r drop-vs, eval = FALSE}
eqvs_drop(
  country    = "MY_VS",
  version    = "3L",
  saveOption = 1  # remove from current session only
)
```

## Validation

`eqvs_add()` validates the value set before registration:

- For 3L: checks all 243 health states are present
- For 5L: checks all 3125 health states are present
- Checks values are numeric with no duplicates

## Using custom value sets with crosswalk methods

Custom value sets are fully compatible with all crosswalk
functions:

```{r custom-xw, eval = FALSE}
# Use custom 3L value set with original crosswalk
eqxw(
  eq5d5l_data,
  country   = "MY_VS",
  dim.names = c("mo", "sc", "ua", "pd", "ad")
)
```

## Keeping value sets up to date

Use `update_value_sets()` to automatically check for
and install newly published value sets from the
eq5dsuite online repository:

```{r update-vs, eval = FALSE}
update_value_sets()
```

See `vignette("update-value-sets")` for full details.
