Kolektivni izbor

viewof cond_controls = Inputs.form({
  v1: Inputs.select(["A ▸ B ▸ C","A ▸ C ▸ B","B ▸ A ▸ C","B ▸ C ▸ A","C ▸ A ▸ B","C ▸ B ▸ A"], {value: "A ▸ B ▸ C", label: "Birač 1:"}),
  v2: Inputs.select(["A ▸ B ▸ C","A ▸ C ▸ B","B ▸ A ▸ C","B ▸ C ▸ A","C ▸ A ▸ B","C ▸ B ▸ A"], {value: "B ▸ C ▸ A", label: "Birač 2:"}),
  v3: Inputs.select(["A ▸ B ▸ C","A ▸ C ▸ B","B ▸ A ▸ C","B ▸ C ▸ A","C ▸ A ▸ B","C ▸ B ▸ A"], {value: "C ▸ A ▸ B", label: "Birač 3:"})
})

cond_v1 = cond_controls.v1

cond_v2 = cond_controls.v2

cond_v3 = cond_controls.v3

{
  const parse = (s) => s.split(" ▸ ");
  const voters = [parse(cond_v1), parse(cond_v2), parse(cond_v3)];
  const prefers = (v, x, y) => v.indexOf(x) < v.indexOf(y);
  const pair = (x, y) => {
    let wx = 0, wy = 0;
    for (const v of voters) (prefers(v, x, y) ? wx++ : wy++);
    return wx > wy ? x : y;
  };

  const ab = pair("A","B"), bc = pair("B","C"), ac = pair("A","C");
  const wins = {A:0, B:0, C:0};
  [ab, bc, ac].forEach(w => wins[w]++);
  const condWinner = ["A","B","C"].find(k => wins[k] === 2);
  const isCycle = condWinner === undefined;

  const pos = {A: {x: 0, y: 1}, B: {x: 0.87, y: -0.5}, C: {x: -0.87, y: -0.5}};
  const nodes = ["A","B","C"].map(k => ({id: k, x: pos[k].x, y: pos[k].y}));
  const edges = [["A","B",ab],["B","C",bc],["A","C",ac]].map(([a,b,w]) => {
    const loser = w === a ? b : a;
    return {x1: pos[w].x, y1: pos[w].y, x2: pos[loser].x, y2: pos[loser].y};
  });

  const accent = isCycle ? "#C53030" : "#1C7C54";

  return Plot.plot({
    width: 560,
    height: 380,
    marginTop: 40,
    marginBottom: 50,
    style: {fontSize: "13px", fontFamily: "Public Sans, system-ui, sans-serif", color: "#3A332D", background: "transparent"},
    x: {axis: null, domain: [-1.45, 1.45]},
    y: {axis: null, domain: [-1.2, 1.55]},
    marks: [
      Plot.arrow(edges, {x1: "x1", y1: "y1", x2: "x2", y2: "y2",
        stroke: accent, strokeWidth: 2.5, headLength: 13, inset: 28}),
      Plot.dot(nodes, {x: "x", y: "y", r: 22, fill: "white", stroke: "#1C1916", strokeWidth: 2}),
      Plot.text(nodes, {x: "x", y: "y", text: "id", fontSize: 18, fontWeight: 700, fill: "#1C1916"}),
      Plot.text([isCycle ? "Ciklus — nema stabilnog pobjednika" : `Condorcetov pobjednik: ${condWinner}`],
        {frameAnchor: "top", dy: -28, fill: accent, fontSize: 14, fontWeight: 700}),
      Plot.text([`A vs B → ${ab}      B vs C → ${bc}      A vs C → ${ac}`],
        {frameAnchor: "bottom", dy: 34, fill: "#3A332D", fontSize: 12})
    ]
  });
}

viewof borda_controls = Inputs.form({
  abc: Inputs.range([0, 20], {value: 10, step: 1, width: 150, label: "A ▸ B ▸ C"}),
  acb: Inputs.range([0, 20], {value: 0,  step: 1, width: 150, label: "A ▸ C ▸ B"}),
  bca: Inputs.range([0, 20], {value: 9,  step: 1, width: 150, label: "B ▸ C ▸ A"}),
  bac: Inputs.range([0, 20], {value: 0,  step: 1, width: 150, label: "B ▸ A ▸ C"}),
  cab: Inputs.range([0, 20], {value: 0,  step: 1, width: 150, label: "C ▸ A ▸ B"}),
  cba: Inputs.range([0, 20], {value: 0,  step: 1, width: 150, label: "C ▸ B ▸ A"})
})

{
  const w = borda_controls;
  const groups = [
    {rank: ["A","B","C"], n: w.abc},
    {rank: ["A","C","B"], n: w.acb},
    {rank: ["B","C","A"], n: w.bca},
    {rank: ["B","A","C"], n: w.bac},
    {rank: ["C","A","B"], n: w.cab},
    {rank: ["C","B","A"], n: w.cba}
  ];
  const cands = ["A","B","C"];

  const borda = {A: 0, B: 0, C: 0};
  for (const g of groups) {
    borda[g.rank[0]] += 2 * g.n;
    borda[g.rank[1]] += 1 * g.n;
    borda[g.rank[2]] += 0 * g.n;
  }

  const prefers = (rank, x, y) => rank.indexOf(x) < rank.indexOf(y);
  const pairCount = (x, y) => d3.sum(groups, g => prefers(g.rank, x, y) ? g.n : 0);
  const beats = (x, y) => {
    const xy = pairCount(x, y), yx = pairCount(y, x);
    return xy > yx ? x : (yx > xy ? y : null);
  };
  const condWinner = cands.find(c => cands.filter(o => o !== c).every(o => beats(c, o) === c));

  const maxB = d3.max(cands, c => borda[c]);
  const bordaWinners = cands.filter(c => borda[c] === maxB && maxB > 0);
  const bordaWinner = bordaWinners.length === 1 ? bordaWinners[0] : null;

  const agree = bordaWinner && condWinner && bordaWinner === condWinner;
  const accent = agree ? "#1C7C54" : "#6B1F26";

  const data = cands.map(c => ({cand: c, score: borda[c], isWin: c === bordaWinner}));
  const condText  = condWinner ? `Condorcetov pobjednik: ${condWinner}` : "Condorcetov pobjednik: nema (ciklus)";
  const bordaText = bordaWinner ? `Bordin pobjednik: ${bordaWinner} (${borda[bordaWinner]} bod.)` : "Bordin pobjednik: neodlučeno";
  const verdict   = (bordaWinner && condWinner) ? (agree ? "Pravila se slažu" : "Pravila se razilaze") : "";

  return Plot.plot({
    width: 580,
    height: 340,
    marginLeft: 52,
    marginTop: 60,
    marginBottom: 44,
    style: {fontSize: "13px", fontFamily: "Public Sans, system-ui, sans-serif", color: "#3A332D", background: "transparent"},
    x: {label: "Kandidat", domain: cands},
    y: {label: "↑ Bordin zbroj", domain: [0, Math.max(10, maxB * 1.18)], grid: true},
    marks: [
      Plot.ruleY([0], {stroke: "#C9C3B8"}),
      Plot.barY(data, {x: "cand", y: "score", fill: d => d.isWin ? "#4A6B5C" : "#C9BBA3"}),
      Plot.text(data, {x: "cand", y: "score", text: d => d.score, dy: -8,
        fontSize: 14, fontWeight: 700, fill: "#1C1916"}),
      Plot.text([bordaText], {frameAnchor: "top", dy: -48, fontSize: 13, fontWeight: 700, fill: "#4A6B5C"}),
      Plot.text([condText],  {frameAnchor: "top", dy: -30, fontSize: 13, fontWeight: 700, fill: "#1C1916"}),
      Plot.text([verdict],   {frameAnchor: "top", dy: -10, fontSize: 14, fontWeight: 700, fill: accent})
    ]
  });
}

viewof lr_controls = Inputs.form({
  g: Inputs.range([1, 9], {value: 6, step: 0.5, width: 230, label: "Vlastiti dobitak g"}),
  l: Inputs.range([1, 9], {value: 4, step: 0.5, width: 230, label: "Tuđi gubitak l"})
})

{
  const g = lr_controls.g, l = lr_controls.l;
  const A = {x: g, y: -l}, B = {x: -l, y: g}, AB = {x: g - l, y: g - l};
  const passes = AB.x > 0 && AB.y > 0;

  return Plot.plot({
    width: 460,
    height: 400,
    marginLeft: 50,
    marginTop: 40,
    marginBottom: 44,
    style: {fontSize: "12px", fontFamily: "Public Sans, system-ui, sans-serif", color: "#3A332D", background: "transparent"},
    x: {label: "Dobitak / gubitak zastupnika 1 →", domain: [-10, 10]},
    y: {label: "↑ Dobitak / gubitak zastupnika 2", domain: [-10, 10]},
    marks: [
      Plot.rect([{x1: 0, x2: 10, y1: 0, y2: 10}], {x1: "x1", x2: "x2", y1: "y1", y2: "y2", fill: "#4A6B5C", fillOpacity: 0.13}),
      Plot.text([{x: 9.6, y: 9.4}], {x: "x", y: "y", text: ["oba dobivaju"], textAnchor: "end", fill: "#4A6B5C", fontSize: 11, fontWeight: 600}),
      Plot.ruleX([0], {stroke: "#1C1916", strokeWidth: 1}),
      Plot.ruleY([0], {stroke: "#1C1916", strokeWidth: 1}),
      Plot.link([{x1: A.x, y1: A.y, x2: AB.x, y2: AB.y}], {x1: "x1", y1: "y1", x2: "x2", y2: "y2", stroke: "#6B6357", strokeDasharray: "3,3"}),
      Plot.link([{x1: B.x, y1: B.y, x2: AB.x, y2: AB.y}], {x1: "x1", y1: "y1", x2: "x2", y2: "y2", stroke: "#6B6357", strokeDasharray: "3,3"}),
      Plot.dot([A], {x: "x", y: "y", r: 6, fill: "#6B1F26", stroke: "white", strokeWidth: 2}),
      Plot.dot([B], {x: "x", y: "y", r: 6, fill: "#4A6B5C", stroke: "white", strokeWidth: 2}),
      Plot.dot([AB], {x: "x", y: "y", r: 7, fill: "#1C1916", stroke: "white", strokeWidth: 2}),
      Plot.text([A], {x: "x", y: "y", text: ["A"], dx: 12, fontSize: 14, fontWeight: 700, fill: "#6B1F26"}),
      Plot.text([B], {x: "x", y: "y", text: ["B"], dx: -12, fontSize: 14, fontWeight: 700, fill: "#4A6B5C"}),
      Plot.text([AB], {x: "x", y: "y", text: ["A+B"], dy: -14, fontSize: 14, fontWeight: 700, fill: "#1C1916"}),
      Plot.text([`Paket A+B ${passes ? "prolazi (oba dobivaju)" : "pada"}`],
        {frameAnchor: "top", dy: -22, fontSize: 13, fontWeight: 700, fill: passes ? "#1C7C54" : "#6B1F26"})
    ]
  });
}