Initializing a Selection

To initialize a selection, set the init property to a mapping or array of mappings from projected channels or field names to the initial value of the selection. Single selections are initialized with a mapping to single values, multi selections are initialized with a single mapping or an array of mappings to single values, and interval selections are initialized with a single mapping to arrays of values.

Examples

In the example below, we initialize the "brush" selection to the extent of the brush for the x and y encoding channels. The values specify the start and end of the interval selection.

In the example below, we initalize the "CylYr" selection by setting the values for the "Cylinders" and "Years" fields. The values are single values because the selection is a of type single.