R/plot.kstructure.R

In kst: Knowledge Space Theory

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### plot.kstructure.R
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### dependencies: library(relations), library(sets), library(Rgraphviz)
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### 2008-04-17: created
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plot.kstructure <- function(x, ...) {

   ### check if package Rgraphviz is available
   if (!requireNamespace("Rgraphviz", quietly = TRUE)) {
     stop(sprintf("Plotting requires package 'Rgraphviz'."))
   }

   ### check x
   if (!inherits(x, "kstructure")) {
      stop(sprintf("%s must be of class %s.", dQuote("x"), dQuote("kstructure")))
   }

   ### compute structure matrix
   relmat <- set_outer(x, set_is_subset)

   ### plot results
   Rgraphviz::plot(relation(incidence=relmat, domain=x), ...)

}