# Intersections

**Dips** can plot the intersections of planes on the stereonet. The intersection of two planes is a line in 3-dimensional space with **Trend / Plunge** orientation. An intersection line is represented as a point on the stereonet.

Intersections can be plotted as points or Contours on the stereonet.

**To plot intersection points:**

- In the Sidebar
**Plot Options**select the**Intersections**checkbox. - Select the type of Intersection you would like to plot (e.g.,
**Grid Data Planes**,**Set Planes**, etc.).

The intersection types are described below.

## Grid Data Planes

The term "grid data" refers to the planar data in the **Dips** spreadsheet (or Grid Data view). The **Intersections > Grid Data Planes** option will plot the intersections of ALL of the planes in the **Dips** spreadsheet (or Grid Data view). That is, each plane in the file will be intersected against every other plane in the file.

In general, this leads to a large (or very large) number of intersections. Depending on the number of planes in your **Dips** file, the display of all Grid Data Plane intersections may cover most of the stereonet, obscuring other plot data. The maximum number of grid data plane intersections which get displayed can be limited in the Preferences dialog, with the **Maximum Number of Intersections to Display** option.

## All Set Planes

The **Intersections > All Set Planes** option will plot the intersections of ALL planes which belong to sets. That is, each plane belonging to a joint set will be intersected against every other plane belonging to a joint set. This option works for any number of sets (e.g., if you have 3 sets, the planes in all 3 sets will get intersected). Any planes not belonging to sets, are not considered.

## Set vs. Set Planes

The **Intersections >** **Set vs. Set Planes** option allows you to plot the intersections of all planes in any TWO Sets. At least two sets must be defined. When you select the **Set vs. Set Planes** option, a small button will become enabled beside the option. If you select this button, a **Set Intersections** dialog will appear, allowing you to select the two joint sets ( **Set A** and **Set B**) to be intersected.

## User and Mean Set Planes

The **Intersections >** **User and Mean Set Planes** option will plot all possible intersections between all User Planes ( Add User Plane option) and all mean set planes (computed from Sets). User Planes are also intersected with all other user planes, and mean set planes are intersected with all other mean set planes.

## User Planes

The **Intersections >** **User Planes** option will plot all possible intersections of all User Planes ( Add User Plane
option). That is, each User Plane will be intersected with all other User Planes.

## Mean Set Planes

The **Intersections >** **Mean Set Planes** option will plot all possible intersections of all mean set planes (computed from Sets). That is, each Mean Set Plane will be intersected with all other Mean Set Planes. Note that weighted and unweighted mean set planes are considered independently (i.e., weighted planes are NOT intersected with unweighted planes). The applicable planes will depend on the selection of the Terzaghi Weighting option. If **Terzaghi Weighting** is off then only unweighted planes are considered. If **Terzaghi Weighting** is applied then only weighted planes are considered.