Model Parameters

To access this screen:

The Parameters screen displays information about the variogram set for the current estimation scenario. Variables display at the top of the screen in a green, box, for example, in a bivariate case:

The parameters on this screen relate to the selected variable only. Swap between variables in a multivariate case by selecting the relevant green box. A univariate case variable is automatically selected.

Define Model Parameters

The following activity assumes at least one variogram model has been fitted for the active scenario.

To define variogram model parameters for a target estimation variable:

  1. Display the Parameters tab.

  2. For the multivariate case, pick the variable of interest using the green squares displayed at the top of the screen.

    Note: Where multivariate variograms are selected,  if the nugget and/or sill matrices are not positive definite, a warning will be issued indicating the variogram is invalid and that sill and nugget matrices should be reviewed.

  3. Review the Variogram set reference (this is the VREFNUM value associate with the variogram parameters file for the estimation). You can't edit this value.

  4. Review (and edit) the Rotation table.

    This table shows the rotations for the anisotropy axes.

    Choose Angle and Axis for the First, Second and Third rotation. Angle(s) can be between -360 and +360 degrees.

    Note: In the multivariate case all rotations and ranges are the same.

  5. Review the Structure grid.

    This grid displays the nugget and structures for the selected variogram model. All properties other than the fixed Nuggetor Structure index value are editable.

    • Model—The structure type, which can either be Spherical, Gaussian or Exponential.

    • Range X/Y/Z—The ranges for each structure in each axis direction.

    • Variance—The nugget value for each structure.

  6. Add new structures or delete existing ones using the buttons displayed:

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