Array

The Array element is a dynamic container used for repeating elements. It is particularly useful when you need to generate a set of results (like a table or a plot) for each level of a factor or for each variable in a list.

The values of properties can be accessed using the $ operator. For example, to retrieve the title of an array, one can go:

array$title

The methods of an array object are called using the $ operator as well. For example:

array$setVisible(FALSE)

Properties

name

a string specifying the name of the array.

title

a string specifying the title of the array.

visible

TRUE or FALSE, whether the array is visible or not.

status

a string, one of 'complete', 'error', 'inited', 'running'.

state

the state object associated with the array.

Methods

setStatus(status)

sets the array’s status, should be one of 'complete', 'error', 'inited', 'running'.

setVisible(visible=TRUE)

overrides the array’s default visibility.

setTitle(title)

sets the array’s title.

setError(message)

sets the array’s status to ‘error’, and assigns the error message.

setState(object)

sets the state object on the array.

addItem(key)

adds a new item to the array. The key should be a unique identifier for this item. This method returns the newly created element (the template defined in .r.yaml).

get(key)

retrieves an item from the array by its key.

Examples

1. Define the Array in YAML

In your .r.yaml file, you define an Array and provide an items template. This template defines what each element in the array will look like (e.g., a Table).

- name: modelResults
  title: Model Results
  type: Array
  items:
    type: Table
    title: Results for Variable
    columns:
      - name: var
        title: Variable
        type: text
      - name: value
        title: Value
        type: number

2. Implementation in R

In the .run() function of your .b.R file, you can dynamically add items to the array using unique keys. Keys are typically strings (like variable names or factor levels) that uniquely identify each element in the array.

.run = function() {
    array <- self$results$modelResults
    
    # Suppose we want a table for each dependent variable
    deps <- self$options$deps
    
    for (dep in deps) {
        # Create a new instance of the template for this variable
        # The 'key' can be any string that uniquely identifies this item
        table <- array$addItem(key = dep)
        
        # You can now interact with the new table object
        table$setTitle(paste("Results for", dep))
        
        # Add a row to the new table
        table$setRow(rowNo=1, values=list(
            var=dep,
            value=mean(self$data[[dep]], na.rm=TRUE)
        ))
    }
}