Previewing, editing and modeling variograms

To access this area:

In the Variogram dialog, the Variogram Preview area is permanently fixed on the left side of the dialog.

Double-click an existing Variogram plot item or sheet will display the Variogram dialog.

The Variogram dialog's preview area is used to view the displayed variograms, interactively fit the current variogram model, interactively position chart components, access the toolbar and context menu:

The Preview Toolbar

The preview area has a dedicated toolbar which can be displayed by selecting the Show Toolbar check box at the bottom of the dialog:

Once enabled, the toolbar is revealed, and can be repositioned as required using drag-and-drop.

The Preview toolbar contains the following functions:

Save as Image: save the current chart image to a standalone image file. Files can be saved in .bmp, .jpg, .jpeg, .tiff, .gif or .emf formats.

Copy to Clipboard: copy the contents of the preview area to the clipboard. This information can be pasted into any external application that supports the pasting of image metadata. For more information on how to paste into external applications, please refer to the relevant documentation for the system in context.

Print: send the displayed chart to any supported local or network printing device. Note that this function will launch your system's proprietary print control dialog, and you should refer to your system documentation for more details on how to set up particular printing formats for your hardware.

Print Preview: preview the print the Print Preview dialog. More...

3D Mode: enable/disable 3D chart mode. If this option is enabled, you can rotate the chart in the preview area by dragging the mouse with the right-button held down. If the option is disabled, a 2D flat view will be set and no rotation can be performed.

Show/Hide Legend: show/hide the chart legend; it is displayed by default.

If a chart legend is displayed, you can double-click the legend item's legend block or label in the preview panel to open up theChart Series Styledialog orLegend Propertiesdialog respectively, for further formatting options.

Context Menu Options

Right-clicking in the preview area displays the following menu:

Field Details:

Tooltips:

These are displayed in a tooltip popup, in the preview pane, when the cursor is hovered over an experimental variogram data point .

Display Value Field: show/hide the value field name(s).

Display Key/Value in Legend: show/hide the key value (if a key field has been specified in the experimental variogram file).

Display AZI Value: show/hide the azimuth for the variogram.

Display DIP Value: show/hide the dip for the variogram.

Display No. of Pairs: show/hide the number of pairs for the data point (shown by default).

Lock Sill Value: select this to fix the upper sill of the model at its current level. Moving the control point for the highest structure will then only change the range. Moving control points for other structures (if any) will change the spatial variances (Ci values).

Lock all C Values: select this option to lock all model variance values. Moving control points will then only change the ranges.

Lock Range Value: select this to lock the current model range values. Moving control points will then only change the spatial variances.

Display Normalized Variograms: if selected then all variogram values will be divided by the statistical variance of the original data. This means that the theoretical sill of each variogram is 1. This is useful if you want to display variograms for different grades on the same chart as it will mean that the variograms are approximately the same scale in the Y direction. If you have previously selected Custom Axis you may need to update the maximum Y value.

Display Symbol at Each Point: show/hide the symbol that is displayed at each experimental variogram point on the chart.

Display Sample Pairs: show/hide the annotation for the number of pairs of samples used to calculate each variogram point.

Display Variance of Samples: show/hide the horizontal line on the chart representing the sample variance statistic. This is often used as a starting point for defining the variogram model sill.

Display Angle in World Coordinate System: toggle between displaying the Local and World coordinate system AZI and DIP values.

Interactive Model Fitting and Positioning of Chart Components

Interactive Variogram Model Fitting

The variogram model control points can be moved interactively using click-and-drag actions; the cursor changes to indicate the permitted movement direction(s). These depend on the type of model control that has been selected and the defined model fitting settings (see note below), and change the model parameters as follows:

Nugget Variance point: move the point vertically up/down to increase/decrease the value.
Spatial Variance/Range points (1-5): move the point(s) vertically up/down to increase/decrease the spatial variance value(s).
Spatial Variance/Range points (1-5): move the point(s) horizontally right/left to increase/decrease the range value(s).

These permitted model point movements i.e. horizontal, vertical or both, are further restricted by the selected Options parameters in the Model Fitting tab.

The example below shows an isotropic two structure spherical variogram model with the nugget and two spatial variance/range points circled:

Interactive Positioning of Chart Components

The following chart components can be repositioned within the confines of the chart using drag-and-drop:

Title box
Legend box
Model Parameters box.

The orientation of the following components can be changed (horizontal or vertical) by double-clicking on the component:

Title box
Model Parameters box.

	Related Topics
	Rotation Parameters in VARFIT and Variogram Charts Scatter Charts