úÎ ³ Û    A PKTree 8Inner nodes have rectangles, leaves are points and data  An n-dimensional hyperrectangle An n-dimensional point !Contruct a tree with no children +Construct a leaf node representing a point "Extract the rectangle from a node Insert a point into a PKTree *K, minimum number of nodes in subdivision )r, number of divisions in each dimension Root of PKTree Point to insert Data that goes with point  &Search for points in some hypercircle Centre of hypercircle Radius of hypercircle Tree to search in          pktree-0.1 Data.PKTreePKTreeNodeLeafInner RectanglePointcell pointCellrectinsert radiusSearch npartition rectContainsinsert'divideUpinstantiateDivisions