Space Property of a Knowledge Structure

Tests for and converts to knowledge space.

kstructure_is_kspace(x)
  kspace(x)

Arguments

x	An R object of class kstructure or (for kspace() only) kbase.

Details

A knowledge structure is considered a knowledge space if it includes one state for the empty set {}, one state for the full set of domain problems Q, and a state for the union of any two knowledge states (i.e., the closure under union).

kstructure_is_kspace takes an arbitrary knowledge structure and tests for its space property.

kspace takes an arbitrary knowledge structure, base, or family of sets and returns the corresponding knowledge space, i.e. its closure under union.

Value

For kstructure_is_kspace a logical value.

For kspace an R object of class kspace where each subset represents one knowledge state of the knowledge space.

References

Doignon, J.-P., Falmagne, J.-C. (1999) Knowledge Spaces. Heidelberg: Springer Verlag.

See also

kstructure, closure.kstructure

Examples

kst <- kstructure(set(set("a"), set("a","b"), set("a","c"), set("d","e"), 
   set("a","b","d","e"), set("a","c","d","e"), set("a","b","c","d","e")))

# test for knowledge space
kstructure_is_kspace(kst)
#> [1] FALSE

# convert to knowledge space
kspace(kst)
#> {{}, {a}, {a, b}, {a, c}, {d, e}, {a, b, c}, {a, d, e}, {a, b, d, e},
#>  {a, c, d, e}, {a, b, c, d, e}}