[CIG-SHORT] [Cig16-pylith] Pylith error final slip

[Brad Aagaard]

Lauriane,

Please send questions related to PyLith to cig-short at geodynamics.org. 
cig16-pylith was for intended only for the CIG16 tutorial.

PyLith calculates the slip at all points of the fault mesh. The spatial 
database provides a means for the user to specify a field (slip) over 
some region (fault). We have multiple implementations of a spatial 
database. UniformDB is for uniform fields over a domain. SimpleDB is 
intended for small collections of points that do not form a logical 
grid. In a SimpleDB you can use nearest interpolation in which PyLith 
will find the closest point in the spatial database to the location of 
interest (point on the fault). With linear interpolation PyLith will 
attempt to find two points on a line (data-dim = 1), three points on a 
triangle (data-dim=2), or four points on a tetrahedron to linear 
interpolate values from the spatial database to the location of 
interest. A SimpleGridDB is a more efficient implementation of a 
SimpleDB for the case of a logical grid and linear interpolation. Please 
see the PyLith manual for more information about each of these spatial 
database implementations, and the examples for how we use them to 
specify fields over the domain, fault, or boundary.

When you get the error message

"RuntimeError: Could not find final slip at (  0  -30000  -15000) using
spatial database Final slip."

it means your fault contains this point and PyLith could not find points 
in the spatial database to use to interpolate the final slip field to 
this point.

Regards,
Brad

On 3/27/18 5:15 AM, LAURIANE BAYLE wrote:
> Hi,
>
> I have question about how Pylith chose the location of the points at the
> surface at a plane to calculate the slip.
> Indeed, I calculated the deformation field at a planar fault (2 D), so I
> defined a plan (6 points on the fault) and Pylith interpolate between
> this plan. But I changed the size of my elements which are components of
> my fault. So Pylith asked me other points to do this calcul (but it was
> always 6 points to form a plan).
> I had this message:
> "RuntimeError: Could not find final slip at (  0  -30000  -15000) using
> spatial database Final slip."
>
> I don't understand why the coordinates of my points depends on my size
> of elements on the fault plane and how Pylith chose this points?
> Could you help me?
>
> Thanks in advance,
> Lauriane
> Student in Geophysics