GXTIN class¶
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class
GXTIN
(handle=0)¶ GXTIN class.
The
GXTIN
class calculates the Delaunay triangulation of the positions in a database. This is the “best” set of triangles that can be formed from irregularly distributed points. The serializedGXTIN
files can be used for gridding using the Tin-based Nearest Neighbour Algorithm, or for plotting the Delaunay triangles or Voronoi cells to a map.-
copy
(source)¶ Copy
GXTIN
Parameters: source (GXTIN) – Source GXTIN
New in version 5.0.
License: Geosoft End-User License
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classmethod
create
(vv_x, vv_y, vv_z)¶ This method creates a
GXTIN
object.Parameters: Returns: GXTIN
ObjectReturn type: New in version 5.0.
License: Geosoft End-User License
Note: CreateTIN does the
GXTIN
calculation. The Z values are not required, and a 0-lengthGXVV
can be used to indicate the values are not to be used.
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classmethod
create_s
(bf)¶ Create
GXTIN
from a serialized sourceParameters: bf (GXBF) – GXBF
from which to readGXTIN
Returns: GXTIN
ObjectReturn type: GXTIN New in version 5.0.
License: Geosoft End-User License
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classmethod
export_xml
(tin, crc, file)¶ Export a
GXTIN
object as XMLParameters: New in version 6.0.1.
License: Geosoft End-User License
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get_convex_hull
(ply)¶ Get the convex hull of the
GXTIN
.Parameters: ply (GXPLY) – GXPLY
objectNew in version 5.0.
License: Geosoft End-User License
Note: The convex hull is the outside boundary of the triangulated region.
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get_ipj
(ipj)¶ Get the projection.
Parameters: ipj (GXIPJ) – GXIPJ
in which to place theGXTIN
projectionNew in version 5.0.3.
License: Geosoft End-User License
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get_joins
(vv_joins, vv_index, vv_num)¶ Get joins from a
GXTIN
mesh.Parameters: New in version 5.0.
License: Geosoft End-User License
Note: The join information is returned in three VVs.
All VVs must be type
GS_LONG
.
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get_mesh
(vv)¶ Get lines from a
GXTIN
mesh.Parameters: vv (GXVV) – GXVV
of type GS_D2LINE (returned)New in version 5.0.
License: Geosoft End-User License
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get_nodes
(vvx, vvy, vvz)¶ Get the X,Y locations and Z values of the
GXTIN
nodes.Parameters: New in version 5.0.
License: Geosoft End-User License
Note: If this is not a Z-valued
GXTIN
, the Z values will be dummies.
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get_triangle
(index, x0, y0, x1, y1, x2, y2)¶ Get the locations of the vertices of a specific triangle
Parameters: New in version 5.0.
License: Geosoft End-User License
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get_triangles
(tri_vv_pt1, tri_vv_pt2, tri_vv_pt3)¶ Get the triangle nodes.
Parameters: New in version 8.4.
License: Geosoft End-User License
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get_voronoi_edges
(vv)¶ Get line segments defining Voronoi cells.
Parameters: vv (GXVV) – GXVV
of GS_D2LINE type (create with type -32)New in version 5.0.
License: Geosoft End-User License
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interp_vv
(vvx, vvy, vvz)¶ Interp TINned values using the natural neighbour method.
Parameters: New in version 5.0.
License: Geosoft End-User License
Note: The
GXTIN
have been created using max length =rDUMMY
to ensure that theGXTIN
has a convex hull (otherwise the routine that locates the triangle for a given location may fail). TheGXTIN
must also have been created using the Z values. Values located outside the convex hull are set torDUMMY
. The method is based on the following paper:Sambridge, M., Braun, J., and McQueen, H., 1995, Geophysical parameterization and interpolation of irregular data using natural neighbours: Geophysical Journal International, 122 p. 837-857.
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is_null
()¶ Check if this is a null (undefined) instance
Returns: True if this is a null (undefined) instance, False otherwise. Return type: bool
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is_z_valued
()¶ Does the
GXTIN
contain Z values with each X,Y?Returns: Returns 1 if Z values are defined in the GXTIN
Return type: int New in version 5.0.
License: Geosoft End-User License
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linear_interp_vv
(vvx, vvy, vvz)¶ Interp TINned values using the linear interpolation
Parameters: New in version 5.1.4.
License: Geosoft End-User License
Note: The
GXTIN
have been created using max length =rDUMMY
to ensure that theGXTIN
has a convex hull (otherwise the routine that locates the triangle for a given location may fail). TheGXTIN
must also have been created using the Z values. Values located outside the convex hull are set torDUMMY
.The values are set assuming that each
GXTIN
triangle defines a plane.
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locate_triangle
(t, x, y)¶ Get the index of the triangle containing X, Y.
Parameters: - t (int) – Seed triangle (can be iDummy or <0)
- x (float) – Target X location
- y (float) – Target Y location
Returns: The index of the triangle containing X, Y.
Return type: int
New in version 5.0.
License: Geosoft End-User License
Note: Index returned begins at 0, but could be negative.
-1: If X,Y is not contained in a triangle (or triangle not found)
- -2: If the location is on an edge
This is for “fall-back” purposes only.
Frequently edge positions are located as being part of a triangle, so do not rely on this result to determine if a node position is on an edge.
- -3: If the location is a vertex.
- This is for “fall-back” purposes only in the code. Normal operation is to include a node position inside a triangle, so do not rely on this result to determine if a node position is input.
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nearest_vv
(vvx, vvy, vvz)¶ Interp TINned values using the nearest neighbour.
Parameters: New in version 6.0.
License: Geosoft End-User License
Note: The
GXTIN
have been created using max length =rDUMMY
to ensure that theGXTIN
has a convex hull (otherwise the routine that locates the triangle for a given location may fail). TheGXTIN
must also have been created using the Z values. Values located outside the convex hull are set torDUMMY
.Within each voronoi triangle, the Z value of node closest to the input X,Y location is returned.
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nodes
()¶ Returns the number of nodes in the
GXTIN
Returns: The number of nodes in the GXTIN
Return type: int New in version 5.0.
License: Geosoft End-User License
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range_xy
(x_min, y_min, x_max, y_max)¶ Find the range in X and Y of the TINned region.
Parameters: New in version 5.0.
License: Geosoft End-User License
Note: The TINned range is the range of X and Y covered by the
GXTIN
triangles. It can thus be less than the full X and Y range of the nodes themselves, if a full convex hull is not calculated.
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serial
(bf)¶ Serialize
GXTIN
Parameters: bf (GXBF) – GXBF
in which to writeGXTIN
New in version 5.0.
License: Geosoft End-User License
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set_ipj
(ipj)¶ Set the projection.
Parameters: ipj (GXIPJ) – GXIPJ
to place in theGXTIN
New in version 5.0.3.
License: Geosoft End-User License
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triangles
()¶ Returns the number of triangles in the
GXTIN
.Returns: The number of triangles in the GXTIN
Return type: int New in version 5.0.
License: Geosoft End-User License
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