Initialzing a Selection

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

Examples

In the example below, we inialize the "brush" selection to the extent of the brush for yhe 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.