# Appendix B: Troubleshooting

## Overview

The `*car()` functions include checks to ensure that all data is set up in a way that the model can use. If the checks notice something incompatible with the model, an error will be displayed in the console. Here, we list each possible error for the MSTCAR model, including its reasoning and ways to check and fix your inputs.

## Generic errors and warnings

All checks that are run on the data check for general information, such as extraneous list objects which cannot be used by the model. In these cases, RSTr will not use these parts of the dataset. It is recommended to remove these datasets from the model to prevent unnecessary clutter.

## Errors and warnings with list `data`

- `One or more objects missing from list 'data'`: The `data` object requires a list with two objects: an array `Y` for mortality counts and an array `n` for population counts. These are needed to perform parameter updates inside of the MSTCAR model. Check `names(data)` to see a vector of names that exists inside of your array and fix names accordingly.

- `Data not same dimensions. Ensure dim(Y) == dim(n)`: This error occurs when the arrays fed into the `data` list are not of the same size. Use the `dim()` function to check that the dimensions of your two arrays do line up. You can use the `aperm()` function to rearrange arrays if they have the same set of dimensions on different margins.

- `Invalid Y/n values. Check that all Y's/n's are at least 0 and finite`: While `NA` and `NULL` are accepted values in `Y`, both `Y` and `n` must be comprised of positive finite values. Check your data with `summary()` for a quick look at your minimum values.

## Errors and warnings with list `sp_data`

- `Adjacency different length than data. Ensure length(adjacency) == dim(Y)[1]`: Adjacency information must be present for all regions. Look at the length of your adjacency information: it should line up with the number of rows in your `Y` and `n` arrays.

- `Some regions have no neighbors. Ensure all regions have at least one neighbor`: If a region does not have a neighbor, the model will not run. If working with `list` adjacency information, you can first check which regions have no neighbors by running `which(lapply(adjacency, \(x) all(x == 0)))` and then fixing the regions accordingly. For assistance with fixing the adjacency information, read `vignette("RSTr-adjacency")`.

## `inits` and `priors`

For troubleshooting inputs with `inits` and `priors`, reference `vignette("RSTr-initialvalues")` and `vignette("RSTr-priors")`, respectively.

## `ignore_checks`

If you have input data that you are certain is correct, yet are receiving error messages anyway, set the `ignore_checks` argument to `TRUE` when setting up your model to skip data checks. This is not recommended as it is easy to break RSTr when data isn’t properly checked, and should only be used as a last resort when using RSTr.