hasse {DAKS}

Hasse Diagram of Surmise Relation

Description

hasse plots the Hasse diagram of a surmise relation (more precisely, of its corresponding quotient set).

Usage

hasse(imp, items)

Arguments

imp

a required object of class set representing the set of implications, for instance obtained from a call to iita.

items

a required numeric giving the number of items of the domain taken as basis for imp.

Value

If the arguments imp and items are of required types, hasse produces a plot, and returns a list of the equally informative items.

Note

The function hasse is not capable of plotting equally informative items. This is why equally informative items are returned in a list.

A set of implications, an object of the class set, consists of 2-tuples (i, j) of the class tuple, where a 2-tuple (i, j) is interpreted as 'mastering item j implies mastering item i.'

Author(s)

Anatol Sargin, Ali Uenlue

References

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

Uenlue, A. and Sargin, A. (2010) DAKS: An R package for data analysis methods in knowledge space theory. Journal of Statistical Software, 37(2), 1–31. URL http://www.jstatsoft.org/v37/i02/.

See Also

iita, the interface that provides the three inductive item tree analysis methods under one umbrella. See also DAKS-package for general information about this package.

Examples

## requires the package Rgraphviz from Bioconductor
## users must have installed Graphviz on their computers
## Not run: 
hasse(iita(pisa, v = 2)$implications, 5)

## End(Not run)