4.3.5. Functionality for GIF Models¶
220.127.116.11. Set Unit Name for the Model¶
To set the model unit name, select the GIFmodel object then the menu:
GIFmodel → Edit → Set unit name
NOTE This will not change the values of the units (use the simple calculator to change units)! Simply the unit name.
18.104.22.168. Set Air/Ground Cells in Models¶
There are two ways to assign aircell values to a physical property model.
22.214.171.124.1. OPTION 1: From active model¶
For GEO models and GIF models, the physical property values for the air cells can be manual set through either:
GIF Model → Edit → Assign value to air cells
Geology Model → Change values → Assign value to air cells
Prequisites: An active cell model associated with the model’s mesh.
126.96.36.199.2. OPTION 2: Fill values upward and cut with topography¶
TThis function allows the user to re-define the air/ground interface. First, model values from the top ground cells (from no-data-value) are copied vertically. Secondly, air cells are assigned based on a topography or active model objects.
188.8.131.52. Perform Simple Mathematical Operations on Model Values¶
To perform a simple mathematical operation (i.e., change units), select the GIFmodel object then the menu:
GIFmodel → Edit → Calculate → Simple calculator
184.108.40.206. Perform Mathematical Operations Involving Another Model¶
To perform a mathematic operations involving another model (i.e., sum the values), select the GIFmodel object then the menu:
GIFmodel → Edit → Calculate → Model calculator
220.127.116.11. Replace Value¶
This functionality allows the user to change the physical property value of cells within a GIF model based on their current value. This functionality is accessed through:
GIFmodel → Edit → Replace value
The following fields are then filled in:
Old value: approximate value for cells whose physical property will be replaced
New value: new physical property value for cells being replaced
Tolerance: The extent at which physical property values may differ from old value and be replace by new value
18.104.22.168. Fill No-Data-Values (2D Interpolation)¶
This functionality allows the user to interpolate the physical property values between columns of models. The algorithm first copy ground values upward, then proceed with and inverse distance interpolation between columns of model values.
The following fields control the inverse distance interpolation:
where x and y define the cell center location of model column m in the underlying mesh.
Number of interpolation cells (N): Number of neighboring cells to use in the 2D inverse distance (1=NearestNeighbor)
Threshold parameter (\(\delta\)): Smoothing parameter controlling thresholding the inverse distances
North-South Stretching Factor: Value controlling the stretching of the interpolation along the North-South direction. Increase this value to compensate for East-West oriented models.
East-West Stretching Factor: Value controlling the stretching of the interpolation along the North-South direction. Increase this value to compensate for North-South oriented models.
No-data-value: Value used in the search of empty model columns and air cells for the upward fill
Interpolation type: Perform the weighted averaging in linear or logarithmic space
22.214.171.124. Nearest Neighbour (3D Interpolation)¶
This funcationality will apply nearest neighbour to interpolate the model from one 3D or OcTree mesh to another 3D or OcTree mesh. This functionality is accessed through:
Model → 3D options → Nearest neighbour interpolation
Important parameters for the interpolation and management of cells in the padding are as follows:
Air value: The value given to all cells lying outside the active topography
Padding Cell Options:
Nearest neighbour: All cells within the active topography will be determined via nearest neighbour interpolation
Set padding to constant: All active topography cells in the padding will be assigned a constant value
Decay to constant: Cells in the padding will decay towards a background value according to the following expression
where \(m_0\) is the background value, \(m_i\) is the value if nearest neighbour was applied, \(0 < \eta < 1\) and \(V\) is the volume. For OcTree meshes, \(\eta \in\) [0.8, 0.9] works well. For tensor models, \(\eta \sim\) 0.5 works well.
126.96.36.199. Add Rectangular Block and Polyhedra-Based Structures¶
The property data locations or locations based on data values may be used. Either convex or non-convex polyhedra may be calculated. Select the GIFmodel object then the menu:
Block: GIFmodel → Edit → Add → Rectangular Block
Convex: GIFmodel → Edit → Add → convex polyhedron from PROPdata
Non-convex: GIFmodel → Edit → Add → non-convex polyhedron from PROPdata
A property data (PROPdata) item must be ref:imported <importProp>.
188.8.131.52. Switch Mesh (of equal size)¶
184.108.40.206.1. Create Active Model¶
This functionality will examine the cell values in a GIFmodel and create and ACTIVEmodel object. The ACTIVEmodel keeps track of which cells like below the surface topography. This functionality is accessed through:
GIFmodel → Create → Active model
So long as the size of the mesh is the same, the associated mesh for any model can be changed through either:
Active-cell model → Switch mesh
Geology Model → Switch mesh
GIF Model → Edit → Switch mesh