Creating a Numeric Interpolant

If the data is both regularly and adequately sampled, different interpolants will produce similar results. In practice, however, it is rarely the case that data is so abundant and input is required to ensure an interpolant produces geologically reasonable results. For this reason, only a basic set of parameters are required when a numeric interpolant is first created. Once the model has been created, you can refine the model to factor in real-world observations and account for limitations in the data.

To create a numeric interpolant, right-click on the Interpolants folder and select New Interpolant. The New Interpolant window will be displayed:

This window is divided into four parts that determine the values used to create the interpolant, the interpolant boundary, any compositing options and general interpolant properties. The rest of this topic describes the parameters that can be set when creating a numeric interpolant:

If you are unsure of some settings, most can be changed later. However, the Numeric values object selected when the interpolant is created cannot be changed.

Values Used

In the Values To Interpolate part of the New Interpolant window, you can select the values that will be used and choose whether or not to filter the data and use a subset of those values in the interpolant.

You can build an interpolant from either:

  • Numeric data contained in imported drillhole data.
  • Points data imported into the Points folder.

All suitable data in the project is available from the Numeric values dropdown list.

Applying a Query Filter

If you have defined a query filter and wish to use it to create the interpolant, select the filter from the Query filter list. Once the model has been created, you can remove the filter or select a different filter.

Applying a Surface Filter

All available data can be used to generate the interpolant or the data can be filtered so that only the data that is within the interpolant boundary or another boundary in the project influences the model. The Surface Filter option is enabled by default, but if you wish to use all data in the project, untick the box for Surface Filter. Otherwise, you can select the Interpolant Boundary or another boundary in the project.

You can use both the Query Filter option and the Surface Filter option together.

The Interpolant Boundary

There are several ways to set the Interpolant Boundary:

  • Enter values to set a Custom boundary.
  • Use the controls in the scene to set the Custom boundary dimensions.
  • Select another object in the project from the Enclose Object list, which could be the numeric values object being interpolated. The extents for that object will be used as the basis for the Custom boundary dimensions.
  • Select another object in the project to use as the Interpolant Boundary. Click the Existing model boundary or volume option and select the required object from the dropdown list.

Once the interpolant has been created, you can further modify its boundary. See Adjusting the Interpolant Boundary.

Compositing Options

When numeric values from drillhole data are used to create an interpolant, there are two approaches to compositing that data:

  • Composite the drillhole data, then use the composited values to create an interpolant. If you select composited values to create an interpolant, compositing options will be disabled.
  • Use uncomposited drillhole data to create an interpolant, then apply compositing settings to the interpolated values. If you are interpolating uncomposited values and do not have specific Compositing values in mind, you may wish to leave this option blank as it can be changed once the model has been created.

If you are interpolating points, compositing options will be disabled.

See Numeric Composites for more information on the effects of the Compositing Length and Minimum Coverage settings.

General Interpolant Properties

Set the Surface resolution for the interpolant and whether or not the resolution is adaptive. See Surface Resolution in Leapfrog Geo for more information on the effects of these settings. The resolution can be changed once the interpolant has been created, so setting a value in the New Interpolant window is not vital. A lower value will produce more detail, but calculations will take longer.

The Volumes enclose option determines whether the interpolant volumes enclose Higher Values, Lower Values or Intervals. Again, this option can be changed once the interpolant has been created.

Enter a Name for the new model and click OK.

The Numeric Interpolant in the Project Tree

The new interpolant will be created and added to the Interpolants folder. The new interpolant contains objects that represent different parts of the interpolant:

Other objects may appear in the project tree under the interpolant as you make changes to it.

Interpolant Display

Display the interpolant by:

  • Dragging the interpolant into the scene or right-clicking on the interpolant and selecting View Output Volumes. Both actions display the parent interpolant’s output volumes.
  • Right-clicking on the interpolant and selecting View Isosurfaces.

Once you have created an interpolant, you can adjust its properties by double-clicking on it. You can also double-click on the individual objects that make up the interpolant. See Editing a Numeric Interpolant for more information.

See also:

Numeric Interpolant Statistics

You can view the approximated mean for each output volume by right-clicking on the interpolant and selecting Properties. Click on the Statistics tab:

You can copy the information displayed in the Statistics tab to the clipboard for use in other applications.