{
    "name": "f81",
    "synonyms": ["F81"],
    "result_type": "RevCTMC[a]",
    "call": "SModel.ReversibleMarkov.f81[SModel.Frequency.frequencies_from_dict[a,pi],a]",
    "args": [
        {
            "arg_name": "pi",
            "arg_type": "List[Pair[String,Double]]",
            "default_value": "~dirichlet_on[letters[@a],1.0]",
	    "description": "Letter frequencies"
        },
        {
            "arg_name": "a",
            "arg_type": "a",
            "default_value": "getAlphabet",
	    "description": "The alphabet"
        }
    ],
    "title": "The Felsenstein (1981) rate matrix",
    "description": "Rate matrix with equal exchangabilities, unequal frequencies.",
    "citation":{"type": "article",
		"title": "Evolutionary trees from DNA sequences: A maximum likelihood approach",
		"year": "1993",
		"author": [{"name": "Felsenstein, Joseph"}],
		"journal": {"name": "Journal of Molecular Evolution", "volume": "17", "number": "6", "pages": "368--376"},
		"identifier": [{"type":"doi","id":"10.1007%2FBF01734359"}]
	       },
    "extract": "all"
}
