This function splits choice data into a train and a test part.

## Usage

```
train_test(
x,
test_proportion = NULL,
test_number = NULL,
by = "N",
random = FALSE,
seed = NULL
)
```

## Arguments

- x
An object of class

`RprobitB_data`

.- test_proportion
A number between 0 and 1, the proportion of the test subsample.

- test_number
A positive integer, the number of observations in the test subsample.

- by
One of

`"N"`

(split by deciders) and`"T"`

(split by choice occasions).- random
If

`TRUE`

, the subsamples are build randomly.- seed
Set a seed for building the subsamples randomly.

## Details

See the vignette on choice data for more details.

## Examples

```
### simulate choices for demonstration
x <- simulate_choices(form = choice ~ covariate, N = 10, T = 10, J = 2)
### 70% of deciders in the train subsample,
### 30% of deciders in the test subsample
train_test(x, test_proportion = 0.3, by = "N")
#> $train
#> Simulated data of 70 choices.
#>
#> $test
#> Simulated data of 30 choices.
#>
### 2 randomly chosen choice occasions per decider in the test subsample,
### the rest in the train subsample
train_test(x, test_number = 2, by = "T", random = TRUE, seed = 1)
#> $train
#> Simulated data of 80 choices.
#>
#> $test
#> Simulated data of 20 choices.
#>
```