Global Mean Vector

The Global Mean Vector option in the Sidebar can be used to display the UNWEIGHTED or WEIGHTED Global Mean Plane and Pole Vector of ALL the data in a Dips file.

To display the Global Mean select the Object Visibility > Global Mean checkbox from the Sidebar Plot Options.

The numerical listing of the Global Mean Vector orientation can be found in the Info Viewer.

NOTE: Use caution when using the global mean vector! When poles plot on opposite sides of the stereonet, a mean orientation calculated from the Lower Hemisphere or Upper Hemisphere alone will be incorrect. No vector correction is applied to poles on opposite sides of the stereonet like in the case of Wrapped Sets since the direction of "wrapping" is ambiguous, when considering all poles.

The colour of the Global Mean Plane and Pole can be changed in the Display Options dialog.

Mean Plane Calculation

The calculation of mean planes in Dips is a vector mean. This is not equivalent to a simple numerical mean calculated by averaging Dip and Dip Direction values.

For example, say you have two readings of Dip Direction: 5 degrees and 355 degrees. The true (vector) mean is 0 degrees, whereas the numerical average is 180 degrees.

The Global Mean Vector is equivalent to including ALL of the poles in a single set, and calculating the vector mean (same calculation as for a Set).