Graph User Manual

Graph ► Tasks ► Density Values
a.k.a: Scalars On a Regular 3D Grid

The Density Values Task takes a sequence of scalars and presents them as boxes on a uniform 3D grid. The scalars have values between 0 and 1 and any value outside that range (especially -1) means "no density". By selecting one of the point fill representations densities can be scanned in the z-direction one x-y plane at a time by touch drag over the point fill plot. Here are a few things to note about this task:

The number of density values must equal the dimension values, entered on the Edit Data tool, multiplied together.
The color map in the skin is key to making a good density plot. In particular, transparency is important to see within the density field. Many times a particular density is of interest and the color map can be adjusted so that that particular density value can show up as a unique color in the color map.
Experimenting with the Volume 3D Data Graphic in Graph Builder might help with understanding the Density Values Task.
The 3D perspective graph is intended to give an overall qualitative indication of the data. The Z Splice point fill representation gives a more quantitative representation. Touch-drag over the 3D graph rotates it. While in Z Splice representation touching a density (in the x-y plane) shows its value and touch-drag scans each x-y plane successively.

The figure below diagrams the Density task.

Data Importing and Exporting Formats

The Table Editor cell type is a scalar. The column, row and block-select import format is a list of scalars separated by a delimiter. The grid lengths are set in the Table's Option tool.
The Edit Data (available in Developer Mode only) format is a list of scalars separated by a blank.
The Fetch Data (available in Developer Mode only) format is a list of numbers separated by a blank or an XML structure.

Representations

The Density Values tasks implements the representations described in the following table. Remember that Skins can affect the representation and may even alter the representation to not conform to the following descriptions.

Representation	Description
Perspective Volume	Shows a 3D perspective volumetric plot on a 3D rectilinear coordinate system. Each density value is denoted by a cube on a 3D regular grid. The cube color, which corresponds to density, can be altered using Skins. By selecting color maps with appropriate transparency the density can be semi-translucent so that inner portions of the density can be viewed.
Z Slice	Shows a single plane of the density on a rectilinear coordinate system. In this representation, the z-plane can be panned by touch-drag from left to right.

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