Drillholes Operations

cell_declustering(obj, obj_region, obj_attribute, size_x, size_y, size_z, nb_off)

Compute declustered weights by Cell Declustering algorithm from C. Deutsch.

Parameters:

Name	Type	Description	Default
obj	Drillholes	Object to decluster in x, y, z.	required
obj_region	Optional[str]	Object region or condition to apply declustering.	required
obj_attribute	str	Object attribute to apply declustering.	required
size_x	int	Cell size in x direction.	required
size_y	int	Cell size in y direction.	required
size_z	int	Cell size in z direction.	required
nb_off	int	Number of offsets.	required

Returns:

Type	Description
ndarray	Declustered weights $w_i$ of each data point $i$.

moving_window_declus(obj, obj_region, obj_attribute, diam_x, diam_y, diam_z, geometry)

Compute declustered weights by Moving Window algorithm.

Parameters:

Name	Type	Description	Default
obj	Drillholes	Object to decluster in x, y, z.	required
obj_region	Optional[str]	Object region or condition to apply declustering.	required
obj_attribute	str	Object attribute to apply declustering.	required
diam_x	int	Ellipsoid diameter in x direction.	required
diam_y	int	Ellipsoid diameter in y direction.	required
diam_z	int	Ellipsoid diameter in z direction.	required
geometry	DeclusteringGeometry	Geometry to be used for the window. BALL -> which_in_ball PARALLELEPIPED -> __which_in_parallelepiped	required

Returns:

Type	Description
ndarray	declustered weights $w_i$ of each data point $i$.

Note

• counts the number $n_i$ of samples inside a moving window centered on point $i$.
• weight $w_i$ is $\frac{m_v}{n_i}$ where $m_v$ is the mean of all the $n_i$.

compositing(drillholes, attribute_list, composit_len=2.0, minimum_composit_len=0.0, residual_len=2.0, ref_z_value=None, method=DesurveyingMethod.TANGENTIAL, dip_convention=DipDownward.NEGATIVE, domain_attribute=None)

Regularize drillholes into composites of same lengths.

Compositing regularizes data spacing along a drillhole from top to bottom.

Parameters:

Name	Type	Description	Default
drillholes	Drillholes	GeoLime Drillholes object.	required
attribute_list	List[str]	List of attribute names to be composited.	required
composit_len	float	Length of new composites. Defaults to 2.	2.0
minimum_composit_len	float	Minimum length of coverage in order to be used. Defaults to 0.	0.0
residual_len	float	Minimum residual length setting if residual is added to last one. Defaults to 0.	2.0
ref_z_value	Optional[float]	Elevation value to clip beginning of composit. Defaults to None.	None
method	DesurveyingMethod	Desurveying method.	TANGENTIAL
dip_convention	DipDownward	Convention of dip downward angle sign.	NEGATIVE
domain_attribute	Optional[str]	Property name of the stratigraphic domain.	None

Returns:

Type	Description
Drillholes	Composited Drillholes.

Composite Length

Composite with coverage length shorter than minimum composite length will have a nan composit grade value.

Residual Length

Compositing might return longer drillhole than original. The residual composite is therefore longer or shorter than the composite length. If the last sample is shorter than the residual length it will be added to the previous composite, having a longer last composite. If the last sample is longer than the residual length it will be considered as a separate composite, having a shorter last composite.

Reference Elevation

A reference value can be set in order to adjust the first composite at a certain elevation or its modulo regarding compositing length. This parameter enables to have same spatial limits for Drillholes and estimation grid used later on.

Compositing by Domain

Stratigraphic domains can be specified using domain_attribute argument. Compositing is then performed sequentially on each domain.

Warning

• Domain must be contiguous, meaning there cannot be multiple composite sequences with the same domain name.
• Composites without domain are discarded during compositing.

Compositing Formula

Regularization is done by sum product average (sum of the grade time the length divided by the total length).

find_duplicate(drillholes, max_distance=1.0)

Seek for the duplicates in drillhole - only in (x,y).

Add a new column with an id corresponding to a duplicated group.

Parameters:

Name	Type	Description	Default
drillholes	Drillholes	GeoLime Drillholes object.	required
max_distance	Optional[float]	Maximum radius for search. Defaults to 1.	1.0

Returns:

Type	Description
ndarray	Numpy array containing an id corresponding to a duplicated group for each point (x,y).

SurfaceSequenceEstimator

Object for creating surfaces from a drillhole based on a lithological sequence.

Parameters:

Name	Type	Description	Default
method	SurfaceEstimationMethod	Interpolation variable used.	ELEVATION
interpolator	DrillholesInterpolationMethod	Mathematical interpolator used.	RBF

Attributes:

Name	Type	Description
method	SurfaceEstimationMethod	Interpolation variable used.
interpolator	DrillholesInterpolationMethod	Mathematical interpolator used.
domain_sequence	DrillholesInterpolationMethod	Drillholes domain sequence.

domain_sequence: DrillholesInterpolationMethod property

Return drillholes domain sequence.

interpolator: DrillholesInterpolationMethod property

Return drillholes interpolation method used.

method: SurfaceEstimationMethod property

Return estimation method used.

build_constraints(data, domain_col, domain_sequence)

Build constraints matrix based on drillholes data. Specify minimum and maximum value for each domain for drillholes.

Parameters:

Name	Type	Description	Default
data	Drillholes	Drillholes Object.	required
domain_col	str	Property name of the lithological domain.	required
domain_sequence	List[str]	Sequence of lithological domain from top to bottom.	required

get_constraints(names)

Return Drillholes Constrains.

Parameters:

Name	Type	Description	Default
names	Union[List[str], str]	Domain names to get constraints from.	required

Returns:

Type	Description
ndarray	Drillholes constraints.

surface_creation(grid_surf, interpolator, **kwargs)

Create surfaces from filled constraints matrix and a gridded surface with topographic attribute (elevation data).

Parameters:

Name	Type	Description	Default
grid_surf	GriddedSurface	GriddedSurface used to compute elevation.	required
interpolator	Union[ExternalSurfaceInterpolationMethod, GeolimeSurfaceInterpolationMethod]	Interpolation Method used to compute on GriddedSurface.	required
**kwargs		Extra arguments used by interpolation method.	{}

ClosestPointValue

Bases: SurfaceSequenceEstimator

Deterministic method for creating surfaces from drillholes and constraints matrix.

Parameters:

Name	Type	Description	Default
method	SurfaceEstimationMethod	Interpolation variable used.	ELEVATION
interpolator	DrillholesInterpolationMethod	Mathematical interpolator used.	RBF

Attributes:

Name	Type	Description
method		Interpolation variable used.
interpolator		Mathematical interpolator used.
domain_sequence		Drillholes domain sequence.

compute_thickness(domain)

Compute thickness of a domain based on elevation data.

Parameters:

Name	Type	Description	Default
domain	str	Domain to compute thickness.	required

Returns:

Type	Description
None	Updated constraints matrix.

determine_topography()

Determine fist lithological domain as topography. Needed for interpolation initialization.

Returns:

Type	Description
None	Updated constraints matrix.

Note

Future version might envisage add of topographic data.

fill_constraints()

Fill constraints matrix with a naive interpolation on unknown data and constraint out of bound points with previously computed constraints.

fill_missing_constraint(domain)

Interpolate unknown data on a domain conditioned with known data.

Parameters:

Name	Type	Description	Default
domain	str	Domain to compute thickness.	required

Raises:

Type	Description
NotImplementedError	Given method is not implemented.
ValueError	Constraints has less than 3 points.

Returns:

Type	Description
None	Updated constraints matrix.

fix_constraint_simple(domain)

Update matrix constraints by checking value and threshold.

Parameters:

Name	Type	Description	Default
domain	str	Domain to compute thickness.	required

Returns:

Type	Description
None	Updated constraints matrix.

thickness_to_elevation(domain)

Convert thickness elevation to elevation information.

Parameters:

Name	Type	Description	Default
domain	str	Domain to compute thickness.	required

Returns:

Type	Description
None	Updated constraints matrix.

update_constraints(domain)

Update constraints using information from above and below units.

Parameters:

Name	Type	Description	Default
domain	str	Domain to compute thickness.	required

Returns:

Type	Description
None	Updated constraints matrix.

Note

Future version might envisage add of topographic data.

update_elevation_threshold_below(domain)

Update elevation thresholds of below unit.

Parameters:

Name	Type	Description	Default
domain	str	Domain to compute thickness.	required

Returns:

Type	Description
None	Updated constraints matrix.

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Last update: 2023-10-09