SirRoboGarage/common_libs/tests/run_prediction_quality.nim

## Offline PREDICTION-QUALITY runner — the campaign's measurement sweep.
##
## Reads the recorded live-vs-real-DrussGT corpus, drives each arm over the
## recorded enemy trajectory, and scores every tick×power-bin prediction against
## the aim-independent interception point (see prediction_quality.nim). Owns the
## RANGE-BAND table that is "the bar" for the lead-gain campaign.
##
## NO CLOSED-LOOP CLAIM IS MADE HERE. Every arm below is an open-loop prediction
## scored on a FIXED trajectory. Wins, damage and survival are decided live.
##
## Usage:
##   nim c -r --nimcache:/tmp/nc_j98 common_libs/tests/run_prediction_quality.nim \
##       [--corpus /tmp/tfil_ab2/out] [--limit N] [--timing]
##
## `--limit N` keeps only the first N runs (sorted), for fast iteration.

import std/[os, strformat, strutils, times, math]
import gun_harness/[gun_interface, virtual_bullets, prediction_quality]
import guns/[head_on, pattern_matcher, tm_horizon, lead_gain]

# arm indices (fixed order = fixed output)
const
  A_ORACLE* = 0
  A_ORACLEQ* = 1
  A_HEADON* = 2
  A_PATTERN* = 3
  A_G15* = 4
  A_G20* = 5
  A_G30* = 6
  A_NAIVE* = 7
  A_TMH* = 8
  A_LG* = 9
  # ── Phase 1: the MISSING gain sweep. Gains >= 1 were measured worse at every
  # band in Phase 0; the unexplored region is gain < 1. gain 0.0 is HeadOn
  # (A_HEADON) and gain 1.0 is Pattern (A_PATTERN), so only 0.25/0.50/0.75 are
  # new arms. Their `leadCorr` is IDENTICAL to Pattern's by construction (Pearson
  # correlation is invariant under positive scaling) — printed only to prove it.
  A_G025* = 10
  A_G050* = 11
  A_G075* = 12
  # Phase 1 fixed causal per-band gain rule: the hitProxy-argmax curve measured by
  # the sub-unity sweep ([1,1,1,0,0] == Pattern below 300 px, HeadOn above). This
  # is the rule the corrector must match; it needs no learning (range is known at fire
  # time). The table was selected in-sample from this corpus.
  A_BAND* = 13
  BandGainTable* = [1.0, 1.0, 1.0, 0.0, 0.0]
  ## (The ADE+SBC gun that used to be arm 14 — rack id 17, `guns/bitbrain_net.nim`
  ## — was RETIRED and removed. See `docs/bitbrain_campaign.md` §RETIRED.)
  ArmNames* = ["Oracle", "OracleQuant", "HeadOn", "Pattern", "PatternGain1.5",
               "PatternGain2.0", "PatternGain3.0", "NaiveLinear", "TMHorizon", "LeadGain",
               "PatternGain0.25", "PatternGain0.50", "PatternGain0.75", "PatternBandGain"]

const
  ## The five sub-unity gain arms, in increasing order, resolved to arm indices.
  ## gain 0.0 == HeadOn, gain 1.0 == Pattern.
  GainArmIdx* = [A_HEADON, A_G025, A_G050, A_G075, A_PATTERN]
  GainValues* = [0.0, 0.25, 0.50, 0.75, 1.0]

# ── the naive-linear control (job-95's LIN_M = 4 extrapolation) ──────────────
#
# Velocity = (pos(t) - pos(t-4)) / 4, then iterate the interception equation.
# This is the trivial predictive gun the lead-capture analysis used as its
# ceiling control; it captures ~2x the lead response Pattern does at 450+ and is
# included to resolve that tension against the angular-error ruler.

type
  NaiveLinearGun = object
    hist: array[5, tuple[x, y: float]]
    count: int
    lastTick: int

proc predict*(g: var NaiveLinearGun, state: WorldState,
              bulletSpeed: float): GunPrediction =
  if state.tick != g.lastTick:
    for i in countdown(4, 1): g.hist[i] = g.hist[i - 1]
    g.hist[0] = (state.enemyX, state.enemyY)
    if g.count < 5: inc g.count
    g.lastTick = state.tick
  if g.count < 5 or bulletSpeed <= 0.0:
    return GunPrediction(x: state.enemyX, y: state.enemyY)
  let vx = (g.hist[0].x - g.hist[4].x) / 4.0
  let vy = (g.hist[0].y - g.hist[4].y) / 4.0
  let ox = state.selfX
  let oy = state.selfY
  var t = hypot(state.enemyX - ox, state.enemyY - oy) / bulletSpeed
  for _ in 0..<40:
    t = hypot(state.enemyX + vx * t - ox, state.enemyY + vy * t - oy) / bulletSpeed
  GunPrediction(x: state.enemyX + vx * t, y: state.enemyY + vy * t)

proc onResult*(g: var NaiveLinearGun, e: FeedbackEvent) = discard

# ── runner ───────────────────────────────────────────────────────────────────

type Ctx = object
  c: Corpus
  cont: bool
  pattern: PatternMatcherGun
  naive: NaiveLinearGun
  tmh: TmHorizonGun
  lg: LeadGainGun
  headon: HeadOnGun
  st: WorldState
  enemy: seq[EnemyInfo]

proc runRound(ctx: var Ctx, arms: var seq[ArmAcc], r: int) =
  let c = ctx.c
  let base = int(c.rStart[r]) - c.base
  let cnt = int(c.rCount[r])
  let iEnd = base + cnt
  ctx.enemy[0] = EnemyInfo(id: 1)
  for i in base ..< iEnd:
    let ox = c.sx(i)
    let oy = c.sy(i)
    let localTick = int(c.tick[i]) - int(c.rStart[r])
    ctx.enemy[0].x = c.ex(i)
    ctx.enemy[0].y = c.ey(i)
    ctx.enemy[0].heading = c.eh(i)
    ctx.enemy[0].speed = c.es(i)
    ctx.enemy[0].energy = c.ee(i)
    ctx.enemy[0].lastSeenTick = localTick
    ctx.st.enemyX = c.ex(i)
    ctx.st.enemyY = c.ey(i)
    ctx.st.enemyHeading = c.eh(i)
    ctx.st.enemySpeed = c.es(i)
    ctx.st.enemyEnergy = c.ee(i)
    ctx.st.selfX = ox
    ctx.st.selfY = oy
    ctx.st.selfHeading = c.sh(i)
    ctx.st.selfSpeed = c.ss(i)
    ctx.st.selfEnergy = c.se(i)
    ctx.st.selfRadarHeading = c.sh(i)
    ctx.st.tick = localTick
    let los = bearingDeg(ox, oy, c.ex(i), c.ey(i))
    for bin in 0 ..< len(PowerBins):
      let speed = bulletSpeed(PowerBins[bin])
      let ib = interceptBearing(c, i, iEnd, ox, oy, speed, ctx.cont)
      if not ib.ok:
        for ai in 0 ..< arms.len: skip(arms[ai])
        continue
      let ibq = interceptBearingQuant(c, i, iEnd, ox, oy, speed)
      let rng = ib.range
      let targetLead = wrap180(ib.bearing - los)
      # oracle: aims at the active ruler's true interception point -> 0 error
      arms[A_ORACLE].record(rng, 0.0, targetLead, targetLead)
      # the analyze_lead_capture_by_range.py integer-tick intercept, scored on the
      # SAME ruler: this is what the coarse solve's own oracle would reach.
      let qLead = if ibq.ok: wrap180(ibq.bearing - los) else: targetLead
      arms[A_ORACLEQ].record(rng, wrap180(qLead - targetLead), qLead, targetLead)
      # head-on: aim at the enemy's CURRENT position (worst realistic gun)
      arms[A_HEADON].record(rng, wrap180(los - ib.bearing), 0.0, targetLead)
      # pattern + lead-gain sweep (gain scales Pattern's lead over LOS)
      let pp = ctx.pattern.predict(ctx.st, speed)
      let pb = bearingDeg(ox, oy, pp.x, pp.y)
      let plead = wrap180(pb - los)
      arms[A_PATTERN].record(rng, wrap180(plead - targetLead), plead, targetLead)
      arms[A_G15].record(rng, wrap180(1.5 * plead - targetLead), 1.5 * plead, targetLead)
      arms[A_G20].record(rng, wrap180(2.0 * plead - targetLead), 2.0 * plead, targetLead)
      arms[A_G30].record(rng, wrap180(3.0 * plead - targetLead), 3.0 * plead, targetLead)
      # sub-unity gains (Phase 1) — the region Phase 0 never covered
      arms[A_G025].record(rng, wrap180(0.25 * plead - targetLead), 0.25 * plead, targetLead)
      arms[A_G050].record(rng, wrap180(0.50 * plead - targetLead), 0.50 * plead, targetLead)
      arms[A_G075].record(rng, wrap180(0.75 * plead - targetLead), 0.75 * plead, targetLead)
      # the fixed causal per-band rule (Phase 1 hitProxy-argmax curve)
      let bg = BandGainTable[bandOf(rng)]
      arms[A_BAND].record(rng, wrap180(bg * plead - targetLead), bg * plead, targetLead)
      # naive linear
      let np = predict(ctx.naive, ctx.st, speed)
      let nl = wrap180(bearingDeg(ox, oy, np.x, np.y) - los)
      arms[A_NAIVE].record(rng, wrap180(nl - targetLead), nl, targetLead)
      # TMHorizon
      let tp = predict(ctx.tmh, ctx.st, speed)
      let tl = wrap180(bearingDeg(ox, oy, tp.x, tp.y) - los)
      arms[A_TMH].record(rng, wrap180(tl - targetLead), tl, targetLead)
      # LEADGAIN (Pattern base + per-band learned lead gain)
      let bp = predict(ctx.lg, ctx.st, speed)
      let bl = wrap180(bearingDeg(ox, oy, bp.x, bp.y) - los)
      arms[A_LG].record(rng, wrap180(bl - targetLead), bl, targetLead)

proc runOne(runPath: string, arms: var seq[ArmAcc], shotsCont, shotsQuant: var ShotStat,
            doShots: bool, timing: bool, cont: bool): int =
  let t0 = epochTime()
  let c = loadCorpus(runPath)
  if c.n == 0: return 0
  var ctx = Ctx(
    c: c,
    cont: cont,
    pattern: PatternMatcherGun(),
    naive: NaiveLinearGun(lastTick: -1),
    tmh: initTmHorizonGun(),
    lg: initLeadGainGun(),
    headon: HeadOnGun(),
    st: WorldState(arenaWidth: c.arenaW, arenaHeight: c.arenaH),
    enemy: newSeq[EnemyInfo](1))
  for r in 0 ..< c.rStart.len:
    runRound(ctx, arms, r)
  if doShots:
    let ev = parseEvents(eventsPathFor(runPath))
    for mode in [true, false]:
      let s = validateShots(c, ev, mode)
      var dst = if mode: addr shotsCont else: addr shotsQuant
      dst.hits += s.hits
      dst.misses += s.misses
      dst.hitSumDeg += s.hitSumDeg
      dst.missSumDeg += s.missSumDeg
      dst.hitSumPx += s.hitSumPx
      dst.missSumPx += s.missSumPx
  if timing:
    stderr.writeLine(fmt"  {extractFilename(runPath):<16} ticks={c.n:<7} {epochTime()-t0:>6.2f}s")
  c.n

proc fmt4(x: float): string =
  if x.classify in {fcNan, fcInf, fcNegInf}: "-" else: fmt"{x:.4f}"

proc fmt3(x: float): string =
  if x.classify in {fcNan, fcInf, fcNegInf}: "-" else: fmt"{x:.3f}"

proc main() =
  # The ADE+SBC gun is default OFF (two switches). This arm is the one place
  # that must exercise it, so the ruler turns its master switch on for the whole
  # process — every other arm is unaffected (they never read TR_BITBRAIN_*).
  putEnv(BBN_NET_ENV, "1")
  putEnv(BBN_MINOBS_ENV, "1")
  var corpusRoot = "/tmp/tfil_ab2/out"
  var limit = 0
  var doShots = true
  var timing = false
  var cont = true
  var i = 1
  while i <= paramCount():
    case paramStr(i)
    of "--corpus": inc i; corpusRoot = paramStr(i)
    of "--limit": inc i; limit = parseInt(paramStr(i))
    of "--no-shots": doShots = false
    of "--timing": timing = true
    of "--ruler":
      inc i
      cont = paramStr(i) != "quant"
    else:
      stderr.writeLine("unknown arg: " & paramStr(i))
      quit(2)
    inc i

  var runs = discoverRuns(corpusRoot)
  if limit > 0 and runs.len > limit: runs.setLen(limit)
  if runs.len == 0:
    stderr.writeLine("no runs found under " & corpusRoot)
    quit(1)

  var arms: seq[ArmAcc]
  for nm in ArmNames: arms.add ArmAcc(name: nm)
  var shotsCont, shotsQuant: ShotStat

  var t0 = epochTime()
  var ticks = 0
  for rp in runs:
    ticks += runOne(rp, arms, shotsCont, shotsQuant, doShots, timing, cont)
  let elapsed = epochTime() - t0

  echo "=".repeat(120)
  echo "OFFLINE PREDICTION QUALITY  --  per-gun single-tick aim error vs the true interception point"
  echo "=".repeat(120)
  echo fmt"corpus        : {corpusRoot}"
  let rulerName = if cont: "continuous (physically exact)" else: "integer-tick (analyze_lead_capture_by_range.py)"
  echo fmt"ruler         : {rulerName}"
  echo fmt"runs          : {runs.len}"
  echo fmt"recorded ticks: {ticks}"
  let tickBins = ticks * len(PowerBins)
  echo fmt"tick x bin    : {tickBins}"
  echo fmt"wall time     : {elapsed:.2f}s   ({elapsed / max(1.0, float(tickBins)) * 1000.0:.4f} ms per tick-bin)"
  echo fmt"per-arm speed : {elapsed / max(1.0, float(tickBins)) * 1000.0:.4f} s per 1000 tick-bins per arm"
  echo ""
  echo "NOTE: offline OPEN-LOOP prediction quality only. No win/damage/survival claim."
  echo ""

  # validation block
  echo "=".repeat(120)
  echo "VALIDATION  --  the ruler must pass ALL of these before any number below is trusted"
  echo "=".repeat(120)
  if doShots and shotsCont.hits > 0 and shotsQuant.hits > 0:
    echo fmt"1. recorded shots (OUR actual server-fired bearings vs the SAME interception solve):"
    for mode in [("continuous", shotsCont), ("integer", shotsQuant)]:
      let s = mode[1]
      let sepOk = if separationPx(s) > 2.0: "OK" else: "WEAK"
      echo fmt"   ruler={mode[0]:<11} hits n={s.hits:<6} mean|err|={meanHitDeg(s):>7.3f} deg / {meanHitPx(s):>7.1f} px | " &
           fmt"misses n={s.misses:<6} mean|err|={meanMissDeg(s):>7.3f} deg / {meanMissPx(s):>7.1f} px | " &
           fmt"separation {separationDeg(s):>6.2f}x deg / {separationPx(s):>6.2f}x px -> {sepOk}"
  else:
    echo "1. recorded-shot validation: SKIPPED"
  let oMax = max([arms[A_ORACLE].bands[0].maxAbs, arms[A_ORACLE].bands[1].maxAbs,
                  arms[A_ORACLE].bands[2].maxAbs, arms[A_ORACLE].bands[3].maxAbs,
                  arms[A_ORACLE].bands[4].maxAbs])
  let oOk = if oMax < 1e-6: "OK" else: "BROKEN"
  echo fmt"2. perfect-oracle gun max |err| over all tick-bins = {oMax:.6f} deg  -> {oOk}"
  # ordering check: the static LOS gun must be worse than every predictive gun.
  proc overallMean(arms: seq[ArmAcc], ai: int): float =
    var sAbs = 0.0
    var n = 0
    for b in 0 ..< NBands:
      sAbs += arms[ai].bands[b].sumAbs
      n += arms[ai].bands[b].n
    if n > 0: sAbs / float(n) else: 0.0
  let mHead = overallMean(arms, A_HEADON)
  let mPat = overallMean(arms, A_PATTERN)
  let mTmh = overallMean(arms, A_TMH)
  let mLg = overallMean(arms, A_LG)
  let mLin = overallMean(arms, A_NAIVE)
  let ordOk = mHead > mPat and mHead > mTmh and mHead > mLg
  echo fmt"3. HeadOn (static LOS) mean|err| = {mHead:.3f} deg vs Pattern {mPat:.3f} / TMHorizon {mTmh:.3f} / LeadGain {mLg:.3f}"
  let ordMsg = if ordOk: "OK (static gun worst among real guns)" else: "UNEXPECTED: a predictive gun is worse than static LOS"
  echo fmt"     -> {ordMsg}"
  echo fmt"     NaiveLinear mean|err| = {mLin:.3f} deg (over-leads; see the lead-gain sweep for why a larger"
  echo fmt"     lead *response* does not mean a smaller angular error)"
  echo "4. determinism: run twice and diff stdout (see fixture; verified separately)."
  echo ""

  echo "=".repeat(120)
  echo "THE BAR  --  per-band mean ABSOLUTE angular aim error (deg), RMSE, sign, hit-proxy"
  echo "=".repeat(120)
  echo "hitProxy = fraction of tick-bins with |err| <= atan(18/range) (the angular half-width of the target disc)."
  echo ""
  stdout.write formatArmTable(arms)

  echo ""
  echo "=".repeat(120)
  echo "HEADROOM  --  the direct answer: how far each arm is from the oracle ceiling, per band"
  echo "=" .repeat(120)
  let hdr = "band     Pattern n  Pattern|err|  Pattern hpx   Oracle hpx   headroom pp   naive hpx  TMHoriz hpx  LeadGain hpx"
  echo hdr
  echo "-".repeat(hdr.len)
  for b in 0 ..< NBands:
    let pat = arms[A_PATTERN].bands[b]
    let orc = arms[A_ORACLE].bands[b]
    let hp = pat.hitProxy
    let ohp = orc.hitProxy
    echo fmt"{BandLabels[b]:<9} {pat.n:>8} {fmt3(meanAbs(pat)):>12} {fmt4(hp):>12} {fmt4(ohp):>12} {ohp - hp:>13.4f} {fmt4(arms[A_NAIVE].bands[b].hitProxy):>11} {fmt4(arms[A_TMH].bands[b].hitProxy):>12} {fmt4(arms[A_LG].bands[b].hitProxy):>13}"
  echo ""
  echo "hitProxy = fraction of tick-bins aimed within atan(18/range) of the true interception point."
  echo "headroom pp = oracle hitProxy - Pattern hitProxy = the absolute hit-probability points available"
  echo "to a perfect predictor (the campaign is playing for a slice of this)."
  echo ""
  let hdrq = "band     OracleQuant hpx   integer-solve coarseness"
  echo hdrq
  echo "-".repeat(hdrq.len)
  for b in 0 ..< NBands:
    let oq = arms[A_ORACLEQ].bands[b]
    echo fmt"{BandLabels[b]:<9} {fmt4(oq.hitProxy):>15}   {fmt3(meanAbs(oq)):>10} deg mean |err|"
  echo "(OracleQuant aims at the analyze_lead_capture_by_range.py integer-tick intercept and is scored"
  echo " on the active ruler. On the continuous ruler it measures how much of a gun's 'error' the coarse"
  echo " solve itself would produce; on the integer ruler it is identically zero.)"

  echo ""
  echo "=".repeat(120)
  echo "LEAD-GAIN SWEEP ON PATTERN  --  multiply Pattern's lead (deg over LOS) by a constant"
  echo "=".repeat(120)
  let hdr2 = "band         gain=1.0   gain=1.5   gain=2.0   gain=3.0   best-gain"
  echo hdr2
  echo "-".repeat(hdr2.len)
  for b in 0 ..< NBands:
    let g1 = meanAbs(arms[A_PATTERN].bands[b])
    let g15 = meanAbs(arms[A_G15].bands[b])
    let g20 = meanAbs(arms[A_G20].bands[b])
    let g30 = meanAbs(arms[A_G30].bands[b])
    var best = "1.0"
    var bestV = g1
    if g15 < bestV: bestV = g15; best = "1.5"
    if g20 < bestV: bestV = g20; best = "2.0"
    if g30 < bestV: bestV = g30; best = "3.0"
    echo fmt"{BandLabels[b]:<9} {fmt3(g1):>10} {fmt3(g15):>10} {fmt3(g20):>10} {fmt3(g30):>10}   {best} ({fmt3(bestV)})"

  echo ""
  echo "=".repeat(120)
  echo "PHASE 1 — THE MISSING GAIN SWEEP: Pattern lead x gain in [0.00, 1.00]  (0 = HeadOn, 1 = Pattern)"
  echo "=".repeat(120)
  echo "Format per cell:  mean|err| deg  [hitProxy].  hitProxy is the objective.  gain 0.0 is HeadOn,"
  echo "gain 1.0 is Pattern.  The per-band gain table IS causal to APPLY (range is known at fire time,"
  echo "so a per-band lookup needs no learning); its ESTIMATION from these same runs is in-sample."
  echo ""
  var hdrg = "band      |req| deg"
  for gi in 0 ..< GainValues.len: hdrg.add fmt"  g={GainValues[gi]:.2f} [hpx]"
  hdrg.add "   bestHpx  dHpx    bestErr"
  echo hdrg
  echo "-".repeat(hdrg.len)
  for b in 0 ..< NBands:
    var line = fmt"{BandLabels[b]:<9} {fmt3(meanAbsReq(arms[A_PATTERN].bands[b])):>9}"
    var bestHi = 0
    var bestHp = -1.0
    var bestEi = 0
    var bestEr = Inf
    for gi in 0 ..< GainValues.len:
      let s = arms[GainArmIdx[gi]].bands[b]
      let e = meanAbs(s)
      let hp = s.hitProxy
      line.add fmt"{fmt3(e):>7} [{fmt3(hp)}] "
      if hp > bestHp: bestHp = hp; bestHi = gi
      if e < bestEr: bestEr = e; bestEi = gi
    let patHp = arms[A_PATTERN].bands[b].hitProxy
    line.add fmt"   {GainValues[bestHi]:.2f}  {bestHp-patHp:+.4f}   {GainValues[bestEi]:.2f}"
    echo line
  echo ""
  echo "OPTIMAL GAIN CURVE (hitProxy-argmax per band) and its implied hit-probability gain vs Pattern:"
  var curve = "   gain = [ "
  for b in 0 ..< NBands:
    var bestHi = 0
    var bestHp = -1.0
    for gi in 0 ..< GainValues.len:
      let hp = arms[GainArmIdx[gi]].bands[b].hitProxy
      if hp > bestHp: bestHp = hp; bestHi = gi
    curve.add fmt"{BandLabels[b]}->{GainValues[bestHi]:.2f}  "
    let patHp = arms[A_PATTERN].bands[b].hitProxy
    echo fmt"   {BandLabels[b]:<9} best gain {GainValues[bestHi]:.2f}  hitProxy {bestHp:.4f} vs Pattern {patHp:.4f}  => {bestHp-patHp:+.4f} pp"
  echo curve & "]"
  echo ""
  echo "DIRECT COMPARISON — Pattern vs the FIXED causal per-band rule [1,1,1,0.00,0.00] vs LeadGain (learned online):"
  let hdrd = "band      Pattern hpx   fixed-band hpx   LeadGain hpx   fixed-Pat pp   BB-Pat pp"
  echo hdrd
  echo "-".repeat(hdrd.len)
  for b in 0 ..< NBands:
    let patHp = arms[A_PATTERN].bands[b].hitProxy
    let fixHp = arms[A_BAND].bands[b].hitProxy
    let bbHp  = arms[A_LG].bands[b].hitProxy
    echo fmt"{BandLabels[b]:<9} {patHp:>11.4f} {fixHp:>16.4f} {bbHp:>14.4f} {fixHp-patHp:>+14.4f} {bbHp-patHp:>+10.4f}"
  echo "fixed-band hpx = the [1,1,1,0,0] table applied causally; it was selected in-sample."
  echo "LeadGain is learned online from labels inside each run (cold start at gain 1.0)."
  echo ""
  echo "LEAD CORRELATION PER GAIN (Pearson of applied lead with required lead). Pearson is invariant"
  echo "under positive scaling, so every g>0 column must be IDENTICAL to Pattern; g=0 has no lead and"
  echo "therefore no correlation. If they match, a shrinking gain does NOT add lead information — it"
  echo "only shrinks the magnitude of an uninformative signal (the gain-sweep mechanism)."
  let hdrc = "band      " & "  corr(g)  "
  var hdrc2 = hdrc
  for gi in 1 ..< GainValues.len: hdrc2.add fmt"   g={GainValues[gi]:.2f}"
  echo hdrc2
  for b in 0 ..< NBands:
    var line = fmt"{BandLabels[b]:<9}"
    for gi in 1 ..< GainValues.len:
      line.add fmt"  {fmt3(leadCorr(arms[GainArmIdx[gi]].bands[b])):>8}"
    echo line

  echo ""
  echo "=".repeat(120)
  echo "LEAD INFORMATIVENESS  --  capture slope (regression of applied lead on required lead) and lead correlation"
  echo "=".repeat(120)
  echo "capture slope is job-95's metric (1.0 = perfect proportional response). corr is the Pearson"
  echo "correlation of the arm's lead with the REQUIRED lead: a large slope on an uncorrelated lead is"
  echo "just amplified noise. This is the table that resolves the 'naive-linear captures 2x the lead but"
  echo "hits less' tension."
  echo ""
  let hdr3 = "band      HO |err|  HO |req|   Pat|req|   Pat cap  Pat corr   Lin cap  Lin corr   TMH cap  TMH corr    BB cap   BB corr"
  echo hdr3
  echo "-".repeat(hdr3.len)
  for b in 0 ..< NBands:
    let sp = arms[A_PATTERN].bands[b]
    let sn = arms[A_NAIVE].bands[b]
    let st = arms[A_TMH].bands[b]
    let sb = arms[A_LG].bands[b]
    echo fmt"{BandLabels[b]:<9} {fmt3(meanAbs(arms[A_HEADON].bands[b])):>9} {fmt3(meanAbsReq(arms[A_HEADON].bands[b])):>9} {fmt3(meanAbsReq(sp)):>9} {fmt3(captureSlope(sp)):>10} {fmt3(leadCorr(sp)):>10} " &
         fmt"{fmt3(captureSlope(sn)):>10} {fmt3(leadCorr(sn)):>10} {fmt3(captureSlope(st)):>10} " &
         fmt"{fmt3(leadCorr(st)):>10} {fmt3(captureSlope(sb)):>10} {fmt3(leadCorr(sb)):>10}"

when isMainModule:
  main()