Visualiser-class: Class '"Visualiser"'

In mpia: Meaningful Purposive Interaction Analysis

Description

Every Domain uses a Visualiser to create cartographic plots of the social semantic network it holds: the visualized conceptual map can then be used as a projection surface to display locations, positions, and pathways of learners or their individual, textually represented learning activities.

Fields

domain:

Reverse reference from the visualiser to its domain

type:

The type of the current map plot: one of 'topographic', 'persp', 'wireframe', 'contour'

mode:

The focus of the current map plot: currently only 'terminology' is supported ('incidences' or 'both' would be the alternative)

netcoords:

The exact coordinates of the planar projection (before grid-tiling aggregation for surface elevation)

prestigeTerms:

The prestige scores for the terminology: symmetric matrix with scores for all term pairs

prestigeDocs:

The prestige scores for the incidences: symmetric matrix with scores for all document pairs

wireframe:

The relief contour: a wireframe of elevation levels (resulting from the grid-tiling aggregation of the netcoords)

mapData:

Viewing transformation matrix required for projecting additional visual data into the display area (such as returned by e.g. persp)

perspective:

logical, indicating whether the current plot is using perspective (or whether its plain), default is TRUE

version:

current version number of the Visualiser class (used for updating cached objects)

Generics

summary

signature(object = "Visualiser"): display the key characteristics of the visualisation data held.

Class Methods

initialize(domain, ...):

The constructor, no actual calculation is done in this step

calculateNetCoords(method):

Method used internally to calculate a position through planar projection.

calculateReliefContour(nrow, ncol):

Method used internally to calculate a smoothened wireframe with the elevation levels reflecting the grid square density of the network coordinates (see calculateNetCoords).

plotMap(method, rotated, name, contour, focus):

Display a perspective or plain plot with the knowledge cartographic map.

toponymy(gridsize, method, add, col):

Find interesting places on the map and label them.

topo.colors.pastel(n):

Helper method to create a colour palette of hyposometric tints.

labelFlag(x, y, label, border, bg, cex, box, col, marker.col):

Helper method to plot a label flag onto a particular location on the map.

plotPath(performanceList, col, alpha, label, component.labels, component.arrows, dot.cex, box, connect):

Plot a sequence of markers on the map, each indicating the exact location of a performance. If connect is set to TRUE, a xspline will be used to connect the locations.

plotPerformance(performance, polyMax, col, label, component.labels, component.arrows, dot.cex):

Plot a marker onto the exact location of a performance (and add markers for the top loading terms activated by it). If component.arrows is TRUE, arrows will be plotted starting from the location of the performance and pointing towards the position of the constituting key terms; if it is FALSE, a dot will be plotted (with dot.cex size). polyMax sets the number of component terms to be highlighted, per default 3.

summary():

Display summary statistics about the visualisation data held (use generic summary instead).

print():

Display short info about the object

show():

Display short info about the object

copy(shallow, domain):

This method is required for updating the Visualiser object to newer versions of the class without loosing its data

newDevice(name, pdf, filename):

Standardised interface to open a new plot on the device of choice regardless of operating system

closeDevice():

Standardised interface to close the plot on the device of choice regardless of operating system

Author(s)

Fridolin Wild <[e-mail]>

References

Fridolin Wild (2016): Learning Analytics in R with SNA, LSA, and MPIA, Springer:Berlin.

See Also

Domain, DomainManager, plot, toponymy

Examples

dmgr = DomainManager()
#d = dmgr$get("generic")
data(generic.domain)
dmgr$add(d, title="generic")

summary(d$visualiser)

plot(d)
toponymy(d)

mpia documentation built on May 2, 2019, 4:18 p.m.