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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>Hi All,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I was trying to implement a class deriving from vtkGraphAlgorithm. I used the vtkBoostbreadthFirstSearch as the template for my implementation; however, I did not implement the FillInputPortInformaiton and FillOutputPortInformation. However, when I tested my code, I got the following error message:<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.0pt;font-family:NSimSun'>ERROR: In ..\..\source\Filtering\vtkExecutive.cxx, line 757<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.0pt;font-family:NSimSun'>vtkStreamingDemandDrivenPipeline (01965648): Algorithm vtkUndirectedGraphCPP(01963930) returned failure for request: vtkInformation (01965E08)<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.0pt;font-family:NSimSun'> Debug: Off<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.0pt;font-family:NSimSun'> Modified Time: 23<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.0pt;font-family:NSimSun'> Reference Count: 1<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.0pt;font-family:NSimSun'> Registered Events: (none)<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.0pt;font-family:NSimSun'> Request: REQUEST_DATA_OBJECT<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.0pt;font-family:NSimSun'> ALGORITHM_AFTER_FORWARD: 1<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.0pt;font-family:NSimSun'> FORWARD_DIRECTION: 0<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.0pt;font-family:NSimSun'><o:p> </o:p></span></p><p class=MsoNormal>The following is the testing code to call my implemented class vtkUndirectedGraphCPP:<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.0pt;font-family:"Courier New"'> vtkUndirectedGraphCPP * cpp = vtkUndirectedGraphCPP::New();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.0pt;font-family:"Courier New"'> cpp->SetInput(g);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.0pt;font-family:"Courier New"'> cpp->SetOriginVertex(<span style='color:#FF8000'>0</span>);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.0pt;font-family:"Courier New"'> cpp->SetEdgeCostArrayName(<span style='color:#A31515'>"weights"</span>);<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:9.0pt;font-family:"Courier New"'> cpp->Update();<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:9.0pt;font-family:"Courier New"'><o:p> </o:p></span></p><p class=MsoNormal>Here g is a vtkMutableUndirectedGraph. I did a little bit search and found that I should overwrite RequestDataObject instead of RequestData. This would be quite different from other implementations in vtk. Could anybody help to solve this problem? My VTK version is 5.4.2.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Thanks,<o:p></o:p></p><p class=MsoNormal>Jinzhong<o:p></o:p></p></div></body></html>