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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 Automatic Fitting tab on the right-hand side of the panel.
This panel, part of the Fit Models menu, is used to fit a model to the currently selected variogram. Both univariate and multivariate model fitting is supported, and you can restrict model parameter values using a range of controls, including the ability to add/remove model structures of varying types.
This panel is only visible if Supervisor data is not being imported. You decide this using the Scenario Setup screen.
Note: Advanced Estimation is part of the Studio RM toolset. Additional licensing modules aren't required.
Field Details:
Run auto-fitting: launch the auto-fitting process - an attempt will be made to fit a model to the variogram directions that are ticked for display and are shown as thumbnails on the bottom row of the panel.
Fit multivariate model: where multiple properties are available, this check box will be enabled to allow a multivariate model to be fitted to the selected variogram (whichever type is currently selected in the Variogram Type drop-down list). If disabled, the univariate instance will be assumed.
Set total sill to variance: if this box is ticked the total sill of the model will be set equal to the statistical variance of the samples. If the box is not ticked the total sill will be calculated from the experimental variogram(s).
Minimum nugget %: define the minimum nugget variance as a percentage of the total sill. Setting it to zero will allow a zero nugget variance to be calculated.
Minimum sill % per structure: the sill of each individual structure must exceed the defined minimum percentage of the total sill. This prevents small structures being introduced that have little influence on the total model.
Maximum Structures:enter the maximum number of structures to be included in the variogram model.
Available Structures: a table showing the currently defined model structures is displayed together with tools to Add, Removeor Constrain structures.
Each structure is defined as one of three Structure types: Spherical, Exponential or Gaussian. Min and Max range values can be specified to constrain the range of each structure.
To edit an existing structure, highlight it in the list, select the required values for Structure type, min and max, and then Apply the values.
To add a new structure make sure none of the existing structures are highlighted, select the required values for Structure type, min and max, and then Apply the values.
For more background on variogram model types, click here.
Use nugget from file: use the file browser to import nugget values from an external file. The file must contain at least the two fields NUGGET and GRADE for univariate models and also the field GRADE2 for a multivariate model. A standard model variogram file is therefore acceptable.
