Error Messages

Error: Cannot open file C:\ProgramData\Encom\IGRF.COF

When starting a new project and trying to identify the IGRF parameters by clicking on the IGRF map you may get an error stating that the IGRF.COF file is not present.

ModelVision looks for an epoch file every five years. For dates 2015 and later it will look for the file IGRF.COF, which may not be updated in the ModelVision distribution folder. However you can get around this problem by changing the date back to 2014.9 or earlier.

We have found the following references to IGRF2015.

Tensor Research will continue to monitor the availability of the latest IGRF epoch. As soon as this is finalised and Tensor Research has acquired the new IGRF model, it will be incorporated into ModelVision.

2D Filtering

There is not enough memory to produce a filtered grid.

 Consider the following factors need when choosing a grid size for 2D filtering:

  • The total non-grid data in memory, such as line data.  If you need to process the largest grid possible, then make sure that only the grid data required for processing is loaded in a session.
  • The amount of padding you are using.  The default is 25%, but if using a high pass filter (such as NSS), this can be edited to as low as 5 to 10% if your grid is on the borderline of being too big. When filtering a TMI grid using the NSS filter, it is processed to the full 6 tensor channels (Bx, By, Bz, Bxx, Byy, Bzz) and then the NSS, lambda2 and Phi is computed.  This means that there are at least 10 padded grids in memory during processing plus any intermediate FFT transformed grids.
  • ModelVision is a 32-bit application and the practical memory limit for a session is near 2GB.

UBC Model Mesh Designer

When generating a UBC mesh file in the UBC Model Mesh Designer dialog the following error message(s) appears:

UBC error messages

The directory of the UBC MAG3D or GRAV3D inversion programs can be unique for each user so the location of these programs (.EXE files) must be communicated to ModelVision before beginning a session.
  1. Navigate to the C:\ProgramData\Encom\MVis folder and open the MVISION.INI file in Notepad or another text editor.
  2. In the [DIRECTORIES] section, make an entry like that below (using your UBC program path name):

Polygonal Bodies and Polygroups

polygon error

The above error can occur when multiple polygonal bodies have vertices so close together that they can sometimes become crossed over with another polygon unit below/next to it. To correct the problem, you will need to find the offending vertex. To aid with this task turn Solid Fill off for the Body Display so the you can see all vertices and change the vertical exaggeration in cross-section view (right mouse click and choose “Track 0>Vertical Extent”.

Disconnected Polygroup

Sometimes when a polygroup model is imported back into ModelVision the polygons are no longer linked for editing, despite the Body Properties dialog saying they are or if one of the boundary points of the polygroup is moved it leaves a gap with the adjoining polygon.

There is probably a problem with one of the polygons.  This is likely to be a thin sliver problem where the angle between two sides of a polygon is approaching zero.  Another possibility is a point that was not joined correctly the first time.

To correct the problem, you will need to find the offending vertex.  To aid with this task turn Solid fill off for the Body Display so the you can see all vertices and change the vertical exaggeration in cross-section view (right mouse click and choose “Track 0>Vertical Extent”).

Joint Inversion

When trying to run a joint inversion on tensor data the inversion is terminated with a message that “joint inversion terminated due to a near zero column in the Jacobian matrix”.

The error message occurs occasionally when the joint inversion cannot resolve the matrix.  Usually it is caused by inappropriate free parameters, but occasionally it is caused by a problem with the session file.

If it is the first type of problem, then try shifting the body, freeing up additional parameters, or turning some parameters off.  Try these suggestions one at a time rather than in combination.

If this doesn’t solve the problem, try saving the session, close down ModelVision, restart ModelVision and open the saved session and then try running it again.