Null Pointer Exception - 3rd Gen Tree

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Revision as of 26 March 2013 at 14:06.
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Null Pointer Exception - 3rd Gen Tree

Hiya,

Getting an occasional null pointer exception. I've not worked out why its happening, and looking at the source I can't quite see how it could happen. Call stack looks like

at KDTree.KdNode.addLeafPoint(KdNode.java:70) at KDTree.KdNode.splitLeafNode(KdNode.java:173) at KDTree.KdNode.addLeafPoint(KdNode.java:79) at KDTree.KdNode.addPoint(KdNode.java:63) at KDTree.KdTree.addPoint(KdTree.java:1)

Any ideas?

    Wolfman23:45, 25 March 2013

    Seems that the "points" array is getting set to 'null' in a newly created child node. Assuming you haven't modified the code of the tree, and you're not doing any multithreading things, I can only see one possible cause: *All* of the data points are being put in the same child node, causing the newly created child node to itself be split while the upper level's splitLeafNode is still running. This implies that calculateSplit() is returning true when it shouldn't.

    Could you add code to line 169 to print the list of coordinates stored in the node being split, or use a debugger to obtain similar information? My suspicion is that the coordinates you're putting into the tree are very unusual in some manner, possibly involving NaN values.

      Rednaxela00:28, 26 March 2013
       

      Sorry for the wall of numbers. Here are the values inside the splitLeafNode function:

      Points array: [ [0.27476300750221805, 0.0, 0.5, 0.5, 0.05944248946787964, 0.05944248946787964], [0.27476300750221805, 0.0, 0.5, 0.5, 0.05944248946787964, 0.05944248946787964], [0.27476300750221805, 0.0, 0.5, 0.5, 0.05944248946787964, 0.05944248946787964], [0.27476300750221805, 0.0, 0.5, 0.5, 0.05944248946787964, 0.05944248946787964], [0.27476300750221805, 0.0, 0.5, 0.5, 0.05944248946787964, 0.05944248946787964], [0.27476300750221805, 0.0, 0.5, 0.5, 0.05944248946787964, 0.05944248946787964], [0.27476300750221805, 0.0, 0.5, 0.5, 0.05944248946787964, 0.05944248946787964], [0.27476300750221805, 0.0, 0.5, 0.5, 0.05944248946787964, 0.05944248946787964], [0.27476300750221805, 0.0, 0.5, 0.5, 0.05944248946787964, 0.05944248946787964], [0.27476300750221805, 0.0, 0.5, 0.5, 0.05944248946787964, 0.05944248946787964], [0.27476300750221805, 0.0, 0.5, 0.5, 0.05944248946787964, 0.05944248946787964], [0.27476300750221805, 0.0, 0.5, 0.5, 0.05944248946787964, 0.05944248946787964], [0.27476300750221805, 0.0, 0.5, 0.5, 0.05944248946787964, 0.05944248946787964], [0.27476300750221805, 0.0, 0.5, 0.5, 0.05944248946787964, 0.05944248946787964], [0.27476300750221805, 0.0, 0.5, 0.5, 0.05944248946787964, 0.05944248946787964], [0.27476300750221805, 0.0, 0.5, 0.5, 0.05944248946787964, 0.05944248946787964], [0.27476300750221805, 0.0, 0.5, 0.5, 0.05944248946787964, 0.05944248946787964], [0.27476300750221805, 0.0, 0.5, 0.5, 0.05944248946787964, 0.05944248946787964], [0.27476300750221805, 0.0, 0.5, 0.5, 0.05944248946787964, 0.05944248946787964], [0.27476300750221805, 0.0, 0.5, 0.5, 0.05944248946787964, 0.05944248946787964], [0.27476300750221805, 0.0, 0.5, 0.5, 0.05944248946787964, 0.05944248946787964], [0.27476300750221805, 0.0, 0.5, 0.5, 0.05944248946787964, 0.05944248946787964], [0.27476300750221805, 0.0, 0.5, 0.5, 0.05944248946787964, 0.05944248946787964], [0.27476300750221805, 0.0, 0.5, 0.5, 0.05944248946787964, 0.05944248946787964], [0.25781116652220715, 0.08692892561404503, 0.49442777954156447, 0.525842295924762, 0.06786100210077804, 0.14692687699385826], [0.2578177856998261, 0.08372619661301722, 0.49463837126786636, 0.5064605739811905, 0.06785023783184158, 0.1469334424631162], [0.2578214298492213, 0.08292549845220197, 0.4946909579122118, 0.5016151434952976, 0.06784441533138576, 0.14693385451422164], [0.25782433041558794, 0.08272532316252756, 0.49470410169693013, 0.5004037858738244, 0.06783982767738157, 0.14693272660841677], [0.25782704507786713, 0.0826752795385066, 0.4947073884210326, 0.500100946468456, 0.06783554880964597, 0.14693121360417843], [0.25782971324440696, 0.0826627688903635, 0.4947082111092713, 0.5000252366171141, 0.0678313472047577, 0.14692960432136848], [0.2578323697665857, 0.08265964148995872, 0.4947084178030773, 0.5000063091542785, 0.06782716496882069, 0.14692797097446295], [0.25783502335720493, 0.08265885990173155, 0.49470847049921196, 0.5000015772885695, 0.06782298762433847, 0.14692633161848062], [0.2578376761944629, 0.0826586647665601, 0.49470848469597223, 0.5000003943221424, 0.06781881155096657, 0.14692469076738635], [0.25784032882290964, 0.08265861624464657, 0.49470848926786565, 0.5000000985805355, 0.06781463584332002, 0.14692304954976892], [0.2578429813786835, 0.0826586043760398, 0.49470849143351225, 0.5000000246451339, 0.06781046027498529, 0.14692140824779062], [0.2578456338958197, 0.08265860167075158, 0.4947084929975659, 0.5000000061612835, 0.06780628478936644, 0.1469197669319714], [0.2578482863828274, 0.08265860125628488, 0.49470849441118986, 0.5000000015403209, 0.06780210937228809, 0.1469181256199622], [0.2578509388418348, 0.08265860141451545, 0.49470849578717485, 0.5000000003850803, 0.06779793402021453, 0.14691648431616464], [0.2578535912733745, 0.08265860171591212, 0.49470849715371845, 0.5000000000962701, 0.06779375873223772, 0.14691484302170008], [0.2578562436775801, 0.08265860205309222, 0.4947084985178703, 0.5000000000240675, 0.0677895835081634, 0.146913201736816], [0.257858896054486, 0.08265860239921004, 0.49470849988139254, 0.5000000000060169, 0.06778540834789157, 0.14691156046162138], [0.2578615484041011, 0.0826586027475541, 0.49470850124472593, 0.5000000000015042, 0.06778123325144109, 0.1469099191960998], [0.25786420072642846, 0.08265860309644661, 0.4947085026079805, 0.500000000000376, 0.06777705821881806, 0.1469082779402436], [0.2578668530214694, 0.08265860344546808, 0.4947085039711838, 0.500000000000094, 0.06777288324998178, 0.14690663669408965], [0.25786950528922475, 0.08265860379451359, 0.4947085053343428, 0.5000000000000234, 0.06776870834495623, 0.1469049954576125], [0.25787215752969567, 0.08265860414355704, 0.49470850669745914, 0.5000000000000058, 0.06776453350371553, 0.14690335423083412], [0.2578748097428828, 0.08265860449259181, 0.4947085080605333, 0.5000000000000014, 0.06776035872627743, 0.1469017130137357], [0.25787746192878697, 0.08265860484161626, 0.4947085094235653, 0.5000000000000003, 0.0677561840126425, 0.1469000718063138], [0.2578801140874092, 0.08265860519062998, 0.4947085107865553, 0.5000000000000001, 0.06775200936277642, 0.14689843060859753], null ] bucket capacity is 50 Size is currently 48 Split dimension is 5 Split value is 0.10318817199105064

        Wolfman08:43, 26 March 2013
         

        The last point there is null...

          AW14:50, 26 March 2013
           

          Yes but its index 49, and size is currently 48. :)

            Wolfman15:06, 26 March 2013