Create - New Directional Analysis Entity

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New Directional Analysis Entity

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Description

Description

The Directional Analysis Entity (DAE) is another form of Analysis Surface designed exclusively for computation/display of Intensity data which uses a spherical polar grid with a polar angle range -90° to +90° and an azimuthal angle range -180° to +180°. The DAE results can be shown in the 3D View using the Show in Visualization View feature.

Navigation

A new DAE can be added in the following ways:

•Menu > Create > New Directional Analysis Entity

•Toolbar button:

•Ctrl + Alt + Y

•Right mouse click on the Analysis Surface folder in the object tree and select "New Directional Analysis Entity" from the list menu.

Controls

Control	Inputs / Description	Defaults
Name	Name of Directional Analysis Entity.	Analysis n
Description	Description of Directional Analysis Entity (optional)	Blank
Angular Range
Polar	Min, Max polar angle range (0-180 deg.) and Divisions (pixels) within range.	(-90, +90) 18
Azimuthal	Min, Max azimuthal angle range (0-360 deg.) and Divisions (pixels) within range.	(-180, +180) 36
Polar Axis	The polar axis direction. Polar axis passes through the poles of the sphere.	Y
Other Axis	Axis from which azimuthal angles are measured. Lies in a plane perpendicular to the polar axis.	Z
Autosize To Data	Sets the Polar and Azimuthal angle ranges automatically based upon ray data extents.	Unchecked
Horizontal axis is:	Select which axis is displayed along horizontal in the Chart plot (Polar or Azimuthal).	Polar
Rendering
Draw as	Controls the display of DAE in 3D View. The DAE can be drawn as Grid Lines, a Filled Grid or a Point Grid. The color of the Grid can also be selected here.	Grid Lines
Rendering Radius	Radius (system units) of the DAE grid shown in the 3D View. The radius is purely for visualization purposes.	1
Location/Orientation
List of linear transformations	Sets coordinate system, position/orientation operations in the usual manner.	Global Coordinate System
Ray Selection
List of ray selection criteria	Ray Filter specifications select which subset of rays are to be used in the calculation.	AND \| All Rays

OK	Accept settings and close dialog box.
Cancel	Discard settings and close dialog box.
Apply	Apply settings and keep dialog box open.
Help	Access this Help page.

Application Notes

Axes definitions

The Polar and Other axes are user-selectable and restricted to point along a positive cardinal axis (+X, +Y, or +Z) of a coordinate system. The Q axis is chosen internally such that the cross-product of Other with Q equals the polar axis (see figure below), which forms a right-handed coordinate system with the Other, Q, and Polar axes essentially playing the traditional roles of the X, Y, and Z axes. The angle definitions for the corresponding spherical coordinate system are then:

Other:	X = cos( q )cos( f )
Q:	Y = cos( q )sin( f )
Polar:	Z = sin( q )

where q and f are the polar and azimuthal angles, respectively.

Because of how the Q axis is defined internally, there are some combinations of Polar and Other axes for which the azimuthal angle will be negative when measured toward a positive cardinal axis direction and this potential for sign disagreement can be confusing to those accustomed to a direction cosine-based angle system. The following table lists all possible axis combinations and whether they have sign agreement (i.e., positive azimuthal angles in a positive cardinal axis direction) or sign-disagreement.

Polar	Other	Sign Agreement
X	Y	Yes
Y	Z	Yes
Z	X	Yes
X	Z	No
Y	X	No
Z	Y	No

Values at the poles

Values at the poles are an average of all nearest neighbor slivers. Since the slivers subtend a small solid angle, results tend to be noisy in this region of the plot.