[Insight-users] DeformableRegistration1 used with mesh: ERROR: "A diagonal element is non positive."

[HellWoxX]

Hi all,

I try to use the DeformableRegistration1 example with a mesh file. I have
not modified the source code.
I tried with a very simple example: 4 nodes, 2 triangles and I got this
error: "A diagonal element is non positive."
Below is the complete output, the mesh file and the configuration file.

Any help welcome!

Jean-Baptiste

Output:

fio024 at arachnoid-sl ~/Registration Examples$ ./bin/DeformableRegistration1
config/DeformableRegistration1.cfg
Reading config file...config/DeformableRegistration1.cfg
Example configured. E 10000 rho 10000
 reading moving ./data/Black.png
 reading fixed ./data/Grey.png
WARNING: In
/home/fio024/InsightToolkit-3.12.0/Code/IO/itkAnalyzeImageIO.cxx, line 1345
AnalyzeImageIO (0x967f518): ERROR: Analyze 7.5 File Format Only Allows RPI,
PIR, and RIP Orientation

WARNING: In
/home/fio024/InsightToolkit-3.12.0/Code/IO/itkAnalyzeImageIO.cxx, line 1345
AnalyzeImageIO (0x967d9a8): ERROR: Analyze 7.5 File Format Only Allows RPI,
PIR, and RIP Orientation

 beginning level 0
 scaling 1
 scaling 1
 ElementsPerDim 32 32
 applying loads
 node 1
 node 2
 node 3
 node 4
 allocating deformation field
 load sizes [128, 128]  image [128, 128]
 load sizes [128, 128]  image [128, 128]
 energy 195075
terminate called after throwing an instance of
'itk::fem::FEMExceptionItpackSolver'
  what():
/home/fio024/InsightToolkit-3.12.0/Code/Numerics/FEM/itkFEMLinearSystemWrapperItpack.cxx:659:
Error: A diagonal element is not positive
Aborted


Mesh file:

<MaterialLinearElasticity>
    0        % Global object number
    E : 100  % Young modulus
    A : 1    % Beam crossection area
    I : 1    % Moment of inertia
    nu : 0.2 % Poisson's ratio
    h : 1    % Plate thickness
    RhoC : 1 % Density times capacity
    END:     % End of material
<Node>
    1
    2 25 25
<Node>
    2
    2 25 51
<Node>
    6
    2 51 25
<Node>
    7
    2 51 51
<Element2DC0LinearTriangularMembrane>
    26
    1
    2
    7
    0
<Element2DC0LinearTriangularMembrane>
    42
    1
    7
    6
    0


Config file:

% ---------------------------------------------------------
% Parameters for the single- or multi-resolution techniques
% ---------------------------------------------------------
1       % Number of levels in the multi-res pyramid (1 = single-res)
1       % Highest level to use in the pyramid
 1 1            % Scaling at lowest level of pyramid
 4              % Number of pixels per element
 1.e4           % Elasticity (E)
 1.e4           % Density x capacity (RhoC)
 1              % Image energy scaling (gamma) - sets gradient step size
 2              % NumberOfIntegrationPoints
 1              % WidthOfMetricRegion
 20             % MaximumIterations
% -------------------------------
% Parameters for the registration
% -------------------------------
0 0.99 % Similarity metric (0=mean sq, 1 = ncc, 2=pattern int, 3=MI,
5=demons)
1.0     % Alpha
0       % DescentDirection (1 = max, 0 = min)
0       % DoLineSearch (0=never, 1=always, 2=if needed)
1.e1    % TimeStep
0.5     % Landmark variance
0       % Employ regridding / enforce diffeomorphism ( >= 1 -> true)
% ----------------------------------
% Information about the image inputs
% ----------------------------------
128     % Nx (image x dimension)
128     % Ny (image y dimension)
0       % Nz (image z dimension - not used if 2D)
./data/Black.png % ReferenceFileName
./data/Grey.png % TargetFileName
% -------------------------------------------------------------------
% The actions below depend on the values of the flags preceding them.
% For example, to write out the displacement fields, you have to set
% the value of WriteDisplacementField to 1.
% -------------------------------------------------------------------
0       % UseLandmarks? - read the file name below if this is true
./config/AssociatedDummyLandmarkFile.txt       % LandmarkFileName
./output/MeshTest_                       % ResultsFileName (prefix only)
1       % WriteDisplacementField?
./output/MeshTest_disp_                         % DisplacementsFileName
(prefix only)
1       % ReadMeshFile?
./config/DummyMeshFile.fem                                      %
MeshFileName
END
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