Use a new algorithm using the median average deviation

tools/analyze-damage.mjs

@@ -0,0 +1,105 @@
+/**
+ * Internal script to analyze damage and spit out results.
+ * There isn't enough entries in the database to make a full analysis, some tiers miss some types.
+ * This script only checks for "minions" and "everything else".
+ * Maybe if future book monsters can be part of what we release, we can analyze those too.
+ */
+
+import fs from "fs/promises";
+import path from "path";
+
+const allData = [];
+
+// Read adversary pack data for average damage for attacks
+const adversariesDirectory = path.join("src/packs/adversaries");
+for (const basefile of await fs.readdir(adversariesDirectory)) {
+    if (!basefile.endsWith(".json")) continue;
+    const filepath = path.join(adversariesDirectory, basefile);
+    const data = JSON.parse(await fs.readFile(filepath, "utf8"));
+    if (data?.type !== "adversary" || data.system.type === "social") continue;
+
+    allData.push({
+        name: data.name,
+        tier: data.system.tier,
+        adversaryType: data.system.type,
+        damage: parseDamage(data.system.attack.damage),
+    });
+}
+
+const result = {
+    basic: compileData(allData.filter(d => d.adversaryType !== "minion")),
+    minion: compileData(allData.filter(d => d.adversaryType === "minion")),
+};
+
+console.log(result);
+
+/** Compiles all data for an adversary type (or all entries) */
+function compileData(entries) {
+    // Note: sorting numbers sorts by their string version by default
+    const results = {};
+    for (const tier of [1, 2, 3, 4]) {
+        const tierEntries = entries.filter(e => e.tier === tier);
+        const allDamage = tierEntries.map(d => d.damage).sort((a, b) => a - b);
+        const median = getMedian(allDamage);
+        const residuals = allDamage.map(d => Math.abs(d - median)).sort((a, b) => a - b);
+        results[tier] = {
+            medianDamage: median,
+            damageDeviation: getMedian(residuals),
+        };
+    }
+
+    return results;
+}
+
+function getMedian(numbers) {
+    const medianIdx = numbers.length / 2;
+    return medianIdx % 1 ? numbers[Math.floor(medianIdx)] : (numbers[medianIdx] + numbers[medianIdx - 1]) / 2;
+}
+
+function parseDamage(damage) {
+    const formula = damage.parts
+        .filter(p => p.applyTo === 'hitPoints')
+        .map(p =>
+            p.value.custom.enabled
+                ? p.value.custom.formula
+                : [p.value.flatMultiplier ? `${p.value.flatMultiplier}${p.value.dice}` : 0, p.value.bonus ?? 0]
+                        .filter(p => !!p)
+                        .join('+')
+        )
+        .join('+');
+    return getExpectedDamage(formula);
+}
+
+/**
+ * Given a simple flavor-less formula with only +/- operators, returns a list of damage partial terms.
+ * All subtracted terms become negative terms.
+ */
+function getExpectedDamage(formula) {
+    const terms = formula.replace("+", " + ").replace("-", " - ").split(" ").map(t => t.trim());
+    let multiplier = 1;
+    return terms.reduce((total, term) => {
+        if (term === "-") {
+            multiplier = -1;
+            return total;
+        } else if (term === "+") {
+            return total;
+        }
+
+        const currentMultiplier = multiplier;
+        multiplier = 1;
+        
+        const number = Number(term);
+        if (!Number.isNaN(number)) {
+            return total + currentMultiplier * number;
+        }
+
+        const dieMatch = term.match(/(\d+)d(\d+)/);
+        if (dieMatch) {
+            const numDice = Number(dieMatch[1]);
+            const faces = Number(dieMatch[2]);
+            return total + currentMultiplier * numDice * ((faces + 1) / 2);
+        }
+
+        throw Error(`Unexpected term ${term} in formula ${formula}`);
+    }, 0);
+}