[vtkusers] Re: ValueError: method requires a VTK object

[Lise Angell]

Seems like the error was correct after all (surprise...), I didn't
send a VTK object to the InsertNextCell-method.

Now I would like to use
vtkUnstructuredGrid::InsertNextCell( int type,vtkIdType npts,vtkIdType
*pts), not vtkUnstructuredGrid::InsertNextCell( int type,vtkIdList *
ptIds).


But then I get the error:
  File "readxdr.py", line 456, in mount_vtk_structures
    vtk_u_grid.InsertNextCell(vtk_cell_type, npt,  pt_list)
TypeError: function takes exactly 2 arguments (3 given)

vtk_cell_type: int, npt: int, pt_list: list of ints
Any ideas how I can reach this method (assuming it's not deprecated)?

Lise

---------- Forwarded message ----------
From: Lise Angell <lise.angell at gmail.com>
Date: Oct 18, 2005 2:29 PM
Subject: ValueError: method requires a VTK object
To: vtkusers at vtk.org


I'm building a vtkUnstructuredGrid from values read from a binary file.
When I want to insert info about the element topology in the grid, I
get the following error:

Traceback (most recent call last):
  File "readxdr.py", line 606, in ?
    u_grid = mount_vtk_structures(grid, fields)
  File "readxdr.py", line 462, in mount_vtk_structures
    vtk_u_grid.InsertNextCell(vtk_cell_type, pt_list)
ValueError: method requires a VTK object


I have read the vtk-list postings concerning this (and the FAQ), but I
don't have two conflicting vtk versions, so I don't see why I should
get this error...

I'm running python2.3 (got some problems compiling VTK with python2.4
because of gcc4.0 on Tiger) and VTK from CVS (from Oct.11 2005) on OSX
Tiger (iBookG4).

Hope someone can help me...

Regards,
Lise



Code snippet:
#------------------------------------------------------------------------------------------------------
       nsd = grid.nsd; nno = grid.nno; nel = grid.nel   # grid: GridFE class

       # allocate VTK structures
        vtk_u_grid = vtk.vtkUnstructuredGrid()
        pts = vtk.vtkPoints()
        pts.SetNumberOfPoints(nno)
        data = vtk.vtkDoubleArray()
        data.SetNumberOfValues(nno)

       for i in range (0,nno):
              x = grid.coords[i]
                s = [... get value from file...]
                data.SetValue(i,s)                              # put
field value in VTK object
                pts.SetPoint(i,x)                               # put
points in VTK object

        vtk_u_grid.Allocate(nel, 0)
        vtk_u_grid.SetPoints(pts)
        vtk_u_grid.GetPointData().SetScalars(data)

        # tell the VTK grid structure about the element topology

        for e in range (1, nel):
                < getting cell type (int) and point list (array of ints)>
                vtk_u_grid.InsertNextCell(vtk_cell_type, pt_list)

#------------------------------------------------------------------------------------------------------




--
"Je forme une entreprise qui n'eut jamais d'exemple,
et dont l'exécution n'aura point d'imitateur."  J-J Rousseau