option allows you to add cone traces or "small circles" on the
stereonet. The cones can be centered about any axis, and may represent
friction circles, toppling bounds, etc.The Cone
option allows you to add cone traces or "small circles" on the
stereonet. The cones can be centered about any axis, and may represent
friction circles, toppling bounds, etc.
To use the Cone option:
Select Cone from the toolbar or the Tools
menu.
You will see the Add Cone dialog. This dialog offers three possible methods of adding a cone to the stereonet:
Enter Orientation (cone axis) in dialog and then define cone angle graphically.
Enter Angle (cone angle) in dialog and then define cone orientation graphically.
Enter both orientation and angle in dialog.
These options are described below.
If only the Orientation checkbox is selected (Angle checkbox is not selected), then enter the cone orientation (trend, plunge of axis) in the dialog and select OK. A cone will appear on the stereonet at the desired axis orientation. The cone angle can be entered interactively and graphically with the mouse. As you move the mouse, the cone angle appears as a popup tooltip. When the desired angle is achieved click the mouse to add the cone to the plot.
If only the Angle checkbox is selected (Orientation checkbox is not selected) then enter the cone angle in the dialog and select OK. A cone will appear on the stereonet with the desired angular radius. The cone orientation (axis) can be entered interactively and graphically with the mouse. As you move the mouse, the cone orientation (trend, plunge) appears as a popup tooltip. When the desired orientation is achieved click the mouse to add the cone to the plot.
If both the Orientation and Angle checkboxes are selected, then enter both values in the dialog, select OK and the cone will be immediately added to the stereonet at the desired location and angle, with no further graphical input required.
NOTE:
The cone angle is the acute angle between the cone perimeter and its axis.
The true center of the cone is marked by an x symbol.
If your Projection type is Equal Angle, small circles will appear as true circles on the stereonet. However, the x marking the cone axis will appear off center as the stereonet perimeter is approached.
If your Projection type is Equal Area, small circles will appear elliptical as the stereonet perimeter is approached.
Small circles can be confusing on a two-dimensional projection, so be sure you understand their geometry before using them for interpretation.
Editing Cones
After a Cone has been added, it can be moved, formatted, etc. For example if you click on the cone to select it, you can graphically change the cone orientation by dragging the center point, or change the cone angle by dragging the perimeter of the cone. See the Edit Tools Overview topic for details.
Right Click Options
The following options are available in the right-click menu while graphically adding a Cone:
Pole Snap – this will "snap" the cone to the pole nearest to the cursor location. Only applicable in pole vector mode.
Line – this will display a moving line through the center of the stereonet, which follows the cursor. Note that this line is NOT added to the plot when you add the cone, it is a temporary graphical aid only. If you wish to add a line to the plot, use the Trend Line option.