Numeric Models

The FastRBF algorithm employs interpolation functions to estimate values from known data. From these estimated values, geological surfaces are constructed as part of the model-building process.

With the Numeric Models folder, you can create numeric models and change their parameters.

• An RBF interpolant describes a physical quantity that varies continuously in space. An RBF interpolant can be used to model, for example, RQD data, with isosurfaces values set to represent both high-quality and low-quality rock. See RBF Interpolants.
• A multi-domained RBF interpolant is an RBF interpolant that has a number of individual sub-interpolants that are bounded by the fault blocks or output volumes of a selected geological model. Changes to all sub-interpolants can be made by editing the parent interpolant, while sub-interpolants can be edited to account for local influences on the values used, the trend and interpolation parameters. See Multi-Domained RBF Interpolants.
• A distance function calculates the distance to a set of points, which is useful for restricting processing to a specific region. To do this, create a distance function, select the objects to use, then add at least one buffer. You can then use one of the distance function’s isosurfaces as a lateral extent for another model. See Distance Functions.
• If you have the Geophysics extension, you can create an inverse distance weighted interpolant. This is useful in generating isosurfaces and volumes from larger data sets such as regular or semi-regular grids. See Inverse Distance Weighted (IDW) Grid Interpolants.

Values that can be interpolated include downhole numeric data, composited drilling data and points data. See Interpolant Functions for a general introduction to interpolation.

The rest of this topic describes:

• Copying a Numeric Model
• Creating a Static Copy of a Numeric Model
• Exporting Numeric Model Volumes and Surfaces
• Exporting Numeric Model Midpoints

Importing a Variogram Model

Leapfrog Works can import spheroidal variogram models exported from Snowden Supervisor. The settings that can be imported are:

• The anisotropy settings in the Trend tab
• The Nugget, Total Sill, Base Range and Alpha settings in the Interpolant tab

To import a variogram model, first create an interpolant. Next, right-click on the interpolant and select Import Variogram Parameters. In the window that appears, navigate to the folder that contains the XML file and select it. Click Open. The interpolant will be updated with the parameters in the XML file.

Once the interpolant has been updated, you can edit it further by double-clicking on the interpolant in the project tree.

Copying a Numeric Model

Creating a copy of a numeric model is a useful way of experimenting with changes to a model.

To copy a numeric model, right-click on it in the project tree and select Copy. Enter a name for the copy of the model and click OK. The copy will be added to the project tree.

Creating a Static Copy of a Numeric Model

Creating a static copy preserves a snapshot of a numeric model that does not change, even when changes are made to the data on which the original model was dependent. This is a useful way of storing historical models and comparing models. Static copies can be exported from Leapfrog Works, as described in Exporting Numeric Model Volumes and Surfaces below.

To create a static copy of a numeric model, right-click on it in the project tree and select Static Copy. Enter a name for the copy of the numeric model and click OK. The copy will be added to the Numeric Models folder.

The objects that make up a static copy of a numeric model depend on the type of model:

• For an RBF interpolant, a static copy is made up of a Legend object, a Boundary object, and all isosurfaces and output volumes created in building the model.
• For a multi-domained RBF interpolant, a static copy is made up of a Legend object, a Boundary object, and the output volumes created in building the model. There are also static copies of the sub-interpolants, which are the same as static copies of RBF interpolants.
• For an indicator RBF interpolant, a static copy is made up of a Legend object, a Boundary object, the model’s isosurface and the output volumes.

To view the date a static copy was created, right-click on it in the project tree and select Properties. The date the copy was created is in the General tab.

Exporting Numeric Model Volumes and Surfaces

There are three options for exporting a numeric model’s output volumes and surfaces. These are:

• Export an output volume or a surface as a mesh. Right-click on it in the project tree and click Export. You will be prompted for a file name and location. See Exporting a Single Mesh.
• Export an output volume as a thickness grid. Right-click on it in the project tree and click Export Thickness Grid. See Thickness Grids.
• Export multiple output volumes and surfaces. Right-click on the interpolant in the project tree and select Export. See Exporting Multiple Meshes from Models.

Exporting Numeric Model Midpoints

To export interval midpoints from a numeric model, right-click on the model’s values object () and select Export. Interval midpoints can be exported in the following formats:

• CSV text file (*.csv)
• DXF file (*.dxf)
• Snowden Supervisor CSV file (*.csv)
• Isatis 3D points file (*.asc)
• Drawing Files (2013/LT2013) (*.dwg)

The values exported are the midpoints of each segment, the X-Y-Z values and the hole ID. The Snowden Supervisor and Isatis 3D points formats also include the interval length, when the model has been created from drilling data.

In each case, you will be prompted for a filename and location.

 

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