Fold Analysis

The Fold Analysis option allows you to fit a plane through any selected group of poles.

To use the Fold Analysis option:

1. Select Fold Analysis from the Tools menu.
2. Click and drag the mouse to draw a freehand window around any group of poles.
3. When finished press ENTER or right-click and select Done from the popup menu.
4. The best fit plane will be added to the stereonet and automatically labelled with an ID number and letter "f" for fold analysis plane.

Terzaghi Weighting

The Terzaghi Weighting option can be applied to the best fit plane.

• If the weighting is applied the plane will be labelled "fw" for weighted.
• If the weighting is not applied the plane will be labelled "fm" for mean (unweighted).

Best Fit Statistics

The statistics of the fold analysis plane listed in the Info Viewer are based on the paper by Woodcock and Naylor (1983).

Global Best Fit

To determine the best fit plane of ALL poles in the file, you can select the Global Best Fit option in the Sidebar ( Object Visibility > Global Best Fit). This will determine the best fit plane considering all poles in the file. The plane will be labelled with a "bm" or "bw" identifier according to the application of the Terzaghi Weighting. Statistics for the Global Best Fit plane are also listed in the Info Viewer.