# Selection of Direction

Click the Direction button found on the Detailed tab in the FE Results dialog to define the main direction of the co-ordinate system (more precisely, to define the x-axis). All result values will be given in this rotated co-ordinate system.

All results are shown in nodes or centers of planar elements of the local user defined coordinate system and the selected layer. The layer may be selected on the Parameters tab.

In the Selection of Direction dialog, the following definitions of the local system are available.

• Automatic. If selected, the local system of elements is adopted according to the system defined for each of the panels (see the description of the Local System Orientation dialog box).
• Cartesian. If selected, the local system of elements is adopted according to the globally user defined orthogonal system for all panels. The following options are available according to the X axis of the global system, to the Y axis of the global system, to the Z axis of the global system, and according to a user defined vector.
• Polar. If selected, the local system of elements is adopted according to the globally user defined polar system for all panels. Point with given coordinates or node number determine the system beginning.
• Local (of the cut) - If selected, the local system of elements is adopted according to the local system defined by the cutting line. In the local system, the following applies.
• X axis runs perpendicular to the cutting line.
• Y axis is tangent along the cutting line.
• Z axis is assumed according to the finite element local system.
NoteThe Local (of the cut) option is available in the Selection of Direction dialog only after clicking the Direction X button in the Panel Cuts dialog. This option is not available in the Selection of Direction dialog if this has been opened from the Maps or Table Columns (tables with results) dialogs.

Defining vectors will define the main direction for definition of planar element calculation results. It is projected onto an element, defining the local x axis direction. The vector cannot be perpendicular to the element (parallel to the local z axis). If the vector is projected onto the element as a point, then all results will equal zero.

Typical situations are shown on the drawing below. All elements are laying on the surface of a cylinder. Initially, local x axes are parallel to the meridian. These axes will be redefined using the main direction pointed in the same direction as the global Z axis.