{
    "name": "f3x4",
    "synonyms": [ "F3x4" ],
    "result_type": "List[Pair[String,Double]]",
    "constraints": "Triplets[a,b]",
    "call": "SModel.Codons.f3x4'_frequencies[a,pi1,pi2,pi3]",
    "args": [
        {
            "arg_name": "pi1",
            "arg_type": "List[Pair[String,Double]]",
            "default_value": "~dirichlet_on[letters[getNucleotides[@a]],1.0]",
	    "description": "Nucleotide frequencies for position 1"
        },
        {
            "arg_name": "pi2",
            "arg_type": "List[Pair[String,Double]]",
            "default_value": "~dirichlet_on[letters[getNucleotides[@a]],1.0]",
	    "description": "Nucleotide frequencies for position 2"
        },
        {
            "arg_name": "pi3",
            "arg_type": "List[Pair[String,Double]]",
            "default_value": "~dirichlet_on[letters[getNucleotides[@a]],1.0]",
	    "description": "Nucleotide frequencies for position 3"
        },
        {
            "arg_name": "a",
            "arg_type": "a",
            "default_value":"getAlphabet",
	    "description": "The (codon) alphabet"
        }
    ],
    "description": "The F3x4 model describes codon frequencies pi' in terms of nucleotide frequencies pi1, pi2, and pi3:\n   pi'[ijk] = pi1[i]*pi2[l]*pi3[k].",
    "examples": ["gy94[pi=f3x4]","f3x4[a=codons[dna]]"],
    "see": ["f1x4","gy94"],
    "extract": "all"
}
