d3.brushSelection()

d3.brushSelection(node)

Returns the current brush selection for the specified node. Internally, an element’s brush state is stored as element.__brush; however, you should use this method rather than accessing it directly. If the given node has no selection, returns null. Otherwise, the selection is defined as an array of numbers. For a two-dimensional brush, it is [[x0, y0], [x1, y1]], where x0 is the minimum x-value, y0 is the minimum y-value, x1 is the maximum x-value, and y1 is the maximum y-value. For an x-brush, it is [x0, x1]; for a y-brush, it is [y0, y1].