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Advanced Estimation - Automatic Fitting Automatic fitting of model variograms |
Advanced Estimation - Fit Models - Automatic Fitting
To access this dialog:
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Using the Advanced Estimation dialog, select the Fit Models menu item. Select the Manual Fitting tab on the right-hand side of the panel.
This panel, part of the Fit Models menu, is used to define a model manually, specifying the number of required structures.
This panel is only visible if Supervisor data is not being imported. You decide this using the Scenario Setup screen.
When doing the manual fit, the primary axis of the ellipsoid (local Y), is aligned with the first selected directional variogram on the model reference plane (local dip == 0). The next selected directional variogram will determine the local XY plane of the model orientation, with preference being given to directional variograms on the model reference plane. Once the orientation has been determined, the ellipsoid Y range is set to the maximum average distance of the variogram used to set the primary axis. All other selected variograms are then analysed to find the one with the furthest Z and X coordinates, in local ellipse coordinates. If perpendicular variograms have been selected, this would normally be those, but the calculation can handle non-perpendicular choices as well.
The 2 remaining half-axes of the ellipse are then calculated by pushing the 2 new variograms directions and maximum average distances into a pair of simultaneous equations. If the variograms all lie on the same plane (max ellipsoid Z == 0), then a only the X half axis is calculated and the Z radius is left at zero.
The requested number of structures are then created, using a nugget which is 10% of the variance, a sill which is the variance, and ranges for each axis which are evenly divided between the structures up to half of the ellipse radii.
Providing a model can be fitted manually based on the specified number of structures, the chart on the left-side of the panel will be updated. The Model Parameters tab is also updated. Examples of where a manual 3D model fitting may not be possible are:
- All selected variograms lie on the same plane. This will result in only 2D structures being created.
- If less than 2 variogram directions have been selected on the Fit Models panel
- It is impossible to calculate the model orientation.
If 2D data is specified, Manual Fit will now produce a Range Z equalling 1.
Note: Advanced Estimation is part of the Studio RM toolset. Additional licensing modules aren't required.
Field Details:
Manual Fit: attempt to manually fit a model based on theNo. of structuresspecified below. This button is only enabled if at least 2 variogram direction is selected on theFit Modelspanel, and at least one grade.
