10.6 Network Viewer

The Network Viewer

Figure: The Network Viewer

The Network Viewer (NetView) provides an interactive pseudo-3D view of the network structure. A default view is associated with each network object, although networks may have as many additional NetViews as is necessary. The NetView can be spatially divided into four regions: Actions, Members, View, and Scale.

The NetView contains the following variables which control some of the display features of View and Scale Regions:

10.7 NetView Variables

int skew
The skew controls the pseudo-3d depth dimension of the NetView's units. A skew of zero provides no perceived depth (2D). The default is 0.15.
UnitShape shape
Controls the shape of the units in the NetView and how their values are graphically displayed. This is also available as the Disp Md menu on the right-hand side of the NetView. The possible choices are:

COLOR
A rectangular shape filled with a color from the colorscale corresponding to its value. If the unit's value is less than the minimum value of the colorscale then it will appear as stippled version of the minimum color. Similar stippling will occur it is greater than the maximum value of the colorscale. If the unit contains no value for the selected member it will be displayed as a stippled version of the View Region's background color.

AREA
LINEAR
A rectangular shape filled with a background color corresponding to the midpoint value of the colorscale and a foreground rectangular spiral shape of with an area corresponding to the ratio of the unit's value to maximum range on the scalebar. Unit values above the scalebar's midpoint have spirals filled with the color of the maximum value of the scalebar, while units with values less than the scalebar's midpoint have spirals filled with the color of the minimum value of the scalebar. AREA spirals scale the size of their area with respect their value/scalebarmax ratio. LINEAR spirals scale their width and height linearly with respect to their value/scalebarmax ratio.

FILL
FILL is similar to the AREA UnitShape but instead of a centered spiral area the FILL UnitShape begins covering an area at the bottom of the Unit and "fills" the unit left to right and bottom to top, covering a percentage area of the unit equal to the units value/scalebarmax ratio.

DIR_FILL
This is similar to FILL except that the unit is divided with a horizontal line across the middle. Unit values greater than the midpoint of the colorscale fill the upper half of the unit only, while values less than the midpoint of the colorscale only fill the lower half the unit.

THREE_D
THREE_D Units utilize the pseudo-3D nature of the View Region to create a varying rectangular height field perspective of the unit's value. Unit values greater than the midpoint of the colorscale rise "above" the 3-D plane of the unit and unit values less than the midpoint of the colorscale sink below the 3-D plane of the unit. The units are colored in the same was as the COLOR UnitShape.

ROUND
Round units have a circular or oval shape and are colored in the same way as the COLOR UnitShape.

HGT_FIELD
Like THREE_D, but each of the four corners of a unit are placed at the average height computed from the four adjacent units to that corner. This produces a smoothly-shaped field of height corresponding to average values of units. The units are colored in the same was as the COLOR UnitShape.

HGT_PEAKS
The same as HGT_FIELD, except that the center of the unit has a peak that is exactly the height corresponding to the value of the units.

ColorScale* colorspec
Controls the color spectrum used by the colorscale. (see section 6.18 Color Scale Specifications).
float prjn_arrow_size
Controls the size of the arrowheads at the end of the projections.
float prjn_arrow_angle
Controls the angle (sharpness) of the arrowheads at the end of the projections. Smaller values = sharper arrowheads.
FontSpec layer_font
The X11 specification for the font to use in drawing the layer names in the View Region
FontSpec unit_font
The X11 specification for the font to use in drawing the unit names and values in the View Region.
Label_Group labels
This group contains the arbitrary network labels visible in the View Region. Labels are usually created and place using the "New Label" button in the Action Region, however the can also be directly created in this group. Editing these labels allows the user to change the text or font of the label, using a standard XWindows font specification string.
NetViewGraph_Group idraw_graphics
This group contains the idraw graphics included in the network display -- the menus Load Graphic and Remove Graphic manipulate these objects.
UnitTextDisplay unit_text
Controls whether or not the unit's names and values are overlayed on top of the unit. This variable is also accessible directly in the NetView's Scale Region.
SplitUnitLayout unit_layout
Controls how the units are split when multiple members are selected for display in the Member Region of the NetView.
bool auto_scale
Controls whether or not the range of the scale in the Scale Region automatically adjust to range of values currently on display in the View Region. This variable is also accessible directly in the NetView's Scale Region as a toggle box.
FloatGeometry spacing
Controls the spacing of the units and layers in the View Region. Useful values range from "0" to "1.0".

The NetView provides the following functions on its Action Menu:

ResetProjectionPoints()
Repositions the projection arrows in the NetView using a highly sophisticated positioning algorithm. If for some reason the positions are not quite ideal, the projections may be repositioned using the Move Mode.
ResetLayerNames()
Repositions the Layer Name text in the lower left corner of the Layer Box for each of the layers in the NetView.
LoadGraphic(File name, float scale)
Loads and Idraw image file of name name and scales it by scale. The image is displayed in background of the the View Region.
RemoveGraphics()
Removes all included graphics.

In addition the NetView provides a Selection menu with two sets of complementary functions. The Set version of these sets a given parameter or specification of the objects selected in the NetView. The Show version selects those objects in the NetView which have a given parameter or specification. These are very useful for constructing the network, and providing visual feedback about its state.

Set/ShowUnitSpec(UnitSpec* spec)
The unit specification, for units, groups of units, or layers.
Set/ShowConSpec(ConSpec* spec)
The Connection specification, for projections.
Set/ShowPrjnSpec(PrjnSpec* spec)
The Projection specification, for projections.
Set/ShowPrjnConType(TypeDef* con_type)
The type of Connection object to be created by the projection (con_type of Projection).
Set/ShowPrjnConGpType(TypeDef* con_gp_type)
The type of Con_Group to be created by the projections (con_gp_type of Projection).
Set/ShowLayerSpec(LayerSpec* spec)
The Layer specification, for layers.
Set/ShowLayerUnitType(TypeDef* unit_type)
The type of units to be created by the layer (el_type of the layer).