closure function

Closure of a Knowledge Structure

Computes the closure of knowledge structures.

## S3 method for class 'kstructure'
closure(x, operation=c("union", "intersection"),...)
  ## S3 method for class 'kbase'
closure(x, operation=c("union", "intersection"),...)
  ## S3 method for class 'kfamset'
closure(x, operation=c("union", "intersection"),...)

Arguments

• x: An object of class kstructure, kbase, or kfamset.
• operation: The set operation under which the closure is computed ("union" or "intersection").
• ...: Other arguments to be passed to methods.

Details

The closure method for objects of class kstructure, kbase, or kfamset performs the closure of a knowledge structure, base, or family of sets by computing the "union", "intersection", "complement", or symmetric difference of any two knowledge states. "union" is also used as a basis for the kspace function.

Note

The implementation of union is more efficient than the one in sets.

Returns

An object of the same class as x where each subset represents one knowledge state of the resulting knowledge structure.

References

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

See Also

kstructure, kspace, kbase, kfamset, closure

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")))
closure(kst, operation="union")