table_to_scatter_field

Synopsis

maps the data in an array of DBcolumn to a scattered field.

Input Port

columns[]	array of Data_Array
parent	UIconnection

Parameters

X_Axis	UIoptionMenu	selects a column for the field's X axis
On	UItoggle	if set, use the X axis
Y_Axis	UIoptionMenu	selects a column for the field's Y axis
On	UItoggle	if set, use the Y axis
Z_Axis	UIoptionMenu	selects a column for the field's Z axis
On	UItoggle	if set, use the Z axis
Axis_Setup	UIoptionMenu	selects a column whose axis parameter is to be set
Discrete	UItoggle	toggles the column between discrete and continuous coordinates
Field_Data	UIoptionBox	selects columns for field node data
Data_Setup	UIoptionMenu	selects a column whose data parameter is to be set
sphere_radius	UItoggle	if set, treats node data as a sphere radius

Output Port

out_fld	Mesh_Unif+Node_Data
out_obj	DefaultObject
x_name	string
y_name	string
z_name	string

Description

Table_to_Scattered_Field maps the data in an array of DBcolumn to a 1D, 2D, or 3D scattered field (an unstructured field that can store scattered data). The data to be mapped is usually query data returned by DBquery or Query.

You typically use scattered fields to represent sparse data, whose columns have many missing values, or nonconnected data, in which there are no internal logical connections between database records. When mapping query data to a scattered field, each record is viewed as a separate point that may have several data values associated with it.

You can visualize scattered field data directly using glyph modules. Alternatively, you can map it to the an unstructured field type using a triangulation process (or, in 3D, a tetrahedration process). After mapping it, you can apply most AVS/Express visualization techniques to the results; for example, isosurface, slice, or surface_plot. This type of visualization is suitable mainly for cluster analysis.

Table_to_Scattered_Field provides a number of parameter values that control various aspects of the mapping.

Axis parameters

You use the X_Axis, Y_Axis, and Z_Axis selection menus to select one, two, or three columns that will serve as the coordinate axes of the resulting scattered field. The number of spatial dimensions in the output field will be one, two, or three, respectively. You use the On toggle associated with each menu to turn the corresponding axis on.

You use the Axis_Setup menu to specify a column whose axis parameter you want to set. This parameter value is used when you select the column as a coordinate axis. The Discrete parameter is available. It specifies whether the coordinates along an axis are discrete or continuous.

If you select Discrete, discrete coordinates are used. They are the indices of the rows in a column, rather than the rows' values. Note that every row is assigned its own index value, including duplicate row values. (By comparison, Table_to_Uniform_Field uses only unique values.)

Discrete coordinates are particularly useful with numeric data such as area codes or with string values. For example, if the column contains the string values "John", "Bob", "Bob", "John", "Bill", the coordinates are 0, 1, 1, 0, and 2, where 0 represents "John", 1 represents "Bob", and 2 represents "Bill".

If you deselect Discrete, continuous coordinates are used; that is, each value in the column is treated as a separate coordinate value.

{bmc BULLET.BMP} Continuous coordinates cannot be used with string values.

Data parameters

You use the Field_Data selection menu to select the columns that will become data components in the resulting scattered field. You use Data_Setup to specify a column whose data parameter you want to set. This parameter value is used when you select the column using Field_Data.

The data parameter sphere_radius is available. Selecting sphere_radius for a particular column puts its data components into a field with a special ID. When visualized, the renderer treats this data as sphere radii.

Input

columns[]

parent

Parameters

X_Axis

On

Y_Axis

On

Z_Axis

On

Axis_Setup

Discrete

Field_Data

Data_Setup

sphere_radius

Output Port

out_fld

out_obj

x_name

y_name

z_name

Example

Not available

File

v/db.v

See also related modules