rcgraph

import mir.series: series;

static immutable keys = ["a", "b", "c"];
static immutable data = [
    ["b", "c"],
    ["a"],
    ["b"],
];

static immutable graphValue = [
    [1, 2], // a
    [0],    // b
    [1],    // c
];

assert (series(keys, data).rcgraph == graphValue);