http://projects.scipy.org/scipy/newticket returns an error - with only the unhelpful suggestion to open a ticket: ************** Oops... Trac detected an internal error: OperationalError: database is locked There was an internal error in Trac. It is recommended that you inform your local Trac administrator and give him all the information he needs to reproduce the issue. To that end, you could Create a ticket. The action that triggered the error was: POST: /newticket ************** Is there any other means to register the following bug report? scipy.cluster.hierarchy.ClusterNode.pre_order returns IndexError for non-root node 0.9.0 To reproduce the error, run the following script: import random, numpy from scipy.cluster.hierarchy import linkage, to_tree datalist = [] for i in range(8000): datalist.append(random.random()) datalist = numpy.array(datalist) datalist = numpy.reshape(datalist, (datalist.shape[0], 1)) Z = linkage(datalist) root_node_ref = to_tree(Z) left_root_node_ref = root_node_ref.left left_root_node_ref.pre_order() The result is: Traceback (most recent call last): File "C:\ReproduceError-pre_order.py", line 12, in <module> left_root_node_ref.pre_order() File "C:\Python27\lib\site-packages\scipy\cluster\hierarchy.py", line 732, in pre_order if not lvisited[ndid]: IndexError: index out of bounds One possible solution (successfully tested with preceding script) is to change pre_order in hierarchy.py as follows: n = self.count curNode = [None] * (2 * n) #following two lines changed: dictionaries instead of lists lvisited = {} rvisited = {} curNode[0] = self k = 0 preorder = [] while k >= 0: nd = curNode[k] ndid = nd.id if nd.is_leaf(): preorder.append(func(nd)) k = k - 1 else: #following line changed: check existence of dictionary key rather than value of list item if ndid not in lvisited.keys(): curNode[k + 1] = nd.left lvisited[ndid] = True k = k + 1 #following line changed: check existence of dictionary key rather than value of list item elif ndid not in rvisited.keys(): curNode[k + 1] = nd.right rvisited[ndid] = True k = k + 1 else: k = k - 1 return preorder Mark Pundurs Data Analyst - Traffic Location & Commerce Chicago The information contained in this communication may be CONFIDENTIAL and is intended only for the use of the recipient(s) named above. If you are not the intended recipient, you are hereby notified that any dissemination, distribution, or copying of this communication, or any of its contents, is strictly prohibited. If you have received this communication in error, please notify the sender and delete/destroy the original message and any copy of it from your computer or paper files.