cna (version 2.2.3)

coherence: Calculate the coherence of complex solution formulas

Description

Calculates the coherence measure of complex solution formulas (csf).

Usage

coherence(cond, tt, type)

Arguments

cond

Character vector specifying an asf or csf.

tt

Data frame or truthTab.

type

Character vector specifying the type of tt: "cs" (crisp-set), "mv" (multi-value), or "fs" (fuzzy-set). Defaults to the type of tt, if tt is a truthTab or to "cs" otherwise.

Value

Numeric vector of coherence values.

Details

Coherence is a measure for model fit that is custom-built for complex solution formulas (csf). It measures the degree to which the atomic solution formulas (asf) combined in a csf cohere, i.e. are instantiated together in tt rather than independently of one another. More concretely, coherence is the ratio of the number of cases satisfying all asf contained in a csf to the number of cases satisfying at least one asf in the csf. For example, if the csf contains the three asf asf1, asf2, asf3, coherence amounts to | asf1 * asf2 * asf3 | / | asf1 + asf2 + asf3 |, where |...| expresses the cardinality of the set of cases instantiating the corresponding expression. For asf, coherence returns 1. For boolean conditions (see condition), the coherence measure is not defined and coherence hence retuns NA. For multiple csf that do not have a factor in common, coherence returns the minimum of the separate coherence scores.

See Also

cna, condition, selectCases, allCombs, full.tt, condTbl

Examples

# NOT RUN {
# Perfect coherence.
dat1 <- selectCases("(A*b <-> C)*(C+D <-> E)")
coherence("(A*b <-> C)*(C + D <-> E)", dat1)
csf(cna(dat1, details = "c"))

# Non-perfect coherence.
dat2 <- selectCases("(a*B <-> C)*(C + D<->E)*(F*g <-> H)")
dat3 <- rbind(tt2df(dat2), c(0,1,0,1,1,1,0,1))
coherence("(a*B <-> C)*(C + D <-> E)*(F*g <-> H)", dat3)
csf(cna(dat3, con=.88, details = "c")) 
# }