Built `common_libs/tm_diag/` as a first-class offline diagnostics kit for Tsetlin
work, BEFORE writing the new gun - because we hit two data problems tonight that no
amount of reading the TM's clauses would have revealed (a 38.8% majority answer,
and 36-58% mislabelled training samples).
WHAT IT PROVIDES
- `feature_spec.nim`: a NAMED feature container, so a learned clause prints as a
sentence (`IF near-wall AND bullet-dead-on AND turn-left(t-2) THEN class=3`)
instead of "feature 17". Includes the 49-bit draft spec from the design session
and the shipped 40-bit encoding.
- `tm_core.nim`: a compact deterministic Granmo multiclass TM with an
INTROSPECTABLE clause layout (mirrors the tm_pattern core).
- `diagnostics.nim`, six groups: (1) pre-flight DATA checks + shuffled-label
control, (2) clause introspection (readable dump, per-clause vote counts, empty
and never-fired clauses, length distribution, per-class balance), (3)
per-feature contribution with an explicit DEAD-INPUT LIST and a ranked
most-valuable list, (4) accuracy vs the majority baseline with per-class
precision/recall and pred-majority share, (5) learning curve, (6) ablation hooks
(drop a block / scramble a bit).
=== TASK 3: THE VALIDATION THAT GATES EVERYTHING - PASSED WITH NUMBERS ===
A diagnostic we never checked is worthless, so the kit was tested on a synthetic
set with a PLANTED RULE (class2 = A and B, class1 = A and not B, class0 = not A),
a deliberately IRRELEVANT block (US, 9 bits) and a PURE-NOISE bit (17).
- majority baseline 60.63% (class0); over-30% correctly flagged
- **the planted rule is recovered EXACTLY** via `necessaryLiterals`:
class0 IF NOT dist-wall<50 | class1 IF dist-wall<50 AND NOT lat DEAD-ON |
class2 IF dist-wall<50 AND lat DEAD-ON
- **DEAD-INPUT LIST = all 9 US bits AND the noise bit 17**, while the planted bits
0 and 45 are correctly NOT listed
- top contributors: bit0 w=1241.7, bit45 w=583.3, then 49.8 - a 12-25x gap, so the
relevant bits are unmistakable
- **ABLATION: drop WALLS -39.47pp, drop BULLETS -19.33pp, drop US 0.00pp**,
scramble A -42.00pp, scramble the noise bit 0.00pp
- shuffled-label control 60.40% vs majority 60.63% = -0.23pp -> no leak
So the kit reliably finds a known dead input and a known relevant one.
=== TASK 4: THE REAL READING, AND A BUG IN THE SHIPPED GUN ===
`tm_pattern` GF head, 6 DrussGT fixtures, pooled 250,745 samples:
- label balance c2 = **34.4%** (majority-heavy, flagged); accuracy **35.72%** vs
majority **34.24%** -> margin **+1.48pp**. On `tr_drussgt_vs_crazy` it is BELOW
majority (33.81% vs 37.72%, -3.92pp).
- 200 clauses: **27 empty, 45 never fired**, mean length 19.17, max 57. The
majority class is starved (class2: 22 non-empty, 18 empty, only 2 positive
fired). Class4 fires 11-24-literal clauses -> memorisation signature.
- **REPRESENTATION BUG FOUND (reported, not silently fixed):** `tmBuildBits` writes
only 38 raw bits into `var bits: array[TM_NBITS=40, uint8]` - bits 38 and 39 are
NEVER ASSIGNED, so they are always 0 and their negated literals are always 1.
The kit's `constantInputs` confirms 38/39 are constant, and **`UNUSED-38`/`39`
rank #6 and #8 in the most-valuable-inputs list** - i.e. the model's
highest-usage inputs are information-free. That is a representation bug, not a
display artefact, and it is a concrete mechanism for part of the poor learning.
DRAFT ENCODING CHECKED: the 49-bit draft is arithmetically consistent
(4+4=8 walls, 6+3=9 us, 3+5+3+3+3+3=20 motion, 5+7=12 bullets = 49). No draft
inconsistency.
Guards: test_tm_diag 48 (new), diag_synthetic 17 (new), test_gun_harness 39,
test_vbullet_metric 11, test_power_selection 3, test_adaptive_radar 41,
test_tfil_ring_weights 24, test_power_policy 26, test_ram_decision 40,
test_rack_membership 48, test_selector_tiebreak 19, test_tm_pattern_registration 20,
test_vbullet_admit_gate 12, acceptance_offline_vs_online 12/12; tm_pattern_learning
passes. The tm_pattern hook is additive and default-OFF (no behaviour change).
NOT YET INCLUDED (the automata metrics discussed for the next step): per-clause
automata settledness (distance from the flip point), clause diversity (pairwise
overlap), literal-set churn over time, and cross-clause vote disagreement. The kit
has clause-level diagnostics but not the automata-state ones.
4.9 KiB
tm_diag — the Tsetlin diagnostics kit
First-class, offline diagnostics for a Tsetlin-Machine head. Answers the two questions that clause-reading alone cannot:
Is the TM learning badly, or is the data bad?
Built before the new TM gun, so a bad design cannot hide behind the data and a bad dataset cannot hide behind the model.
Everything is pure and offline — no battles, no Java, no harness.
Files
| file | contents |
|---|---|
feature_spec.nim |
FeatureSpec, describe, describeClause, draftTMSpec() (49-bit draft), tmPatternSpec() (40-bit shipped encoding) |
tm_core.nim |
compact deterministic Granmo Table 2/3 multiclass TM (mirrors the tm_pattern core), introspectable clause layout |
diagnostics.nim |
the six groups (re-exports the two above) |
Import everything with:
import tm_diag/diagnostics
Task 1 — named features / clause rendering
let spec = draftTMSpec() # 49 bits, all one-hot
spec.nBits # 49
spec.describe(45) # "lat DEAD-ON -18..+18"
spec.describeLiteral(49 + 45) # "NOT lat DEAD-ON -18..+18"
spec.describeClause(@[0, 45], 2) # "IF dist-wall<50 AND lat DEAD-ON -18..+18 THEN class=2"
spec.describeClause(@[], 1) # "IF TRUE (empty clause) THEN class=1"
A block is added with addBlock(name, count, bitNames?); a bit with no explicit
name renders as blockName[k], and a single-bit block renders as its name.
tmPatternSpec() mirrors guns/tm_pattern.nim's tmBuildBits exactly. Its two
last bits (UNUSED-38/39) are a real bug: tmBuildBits writes only 38 raw
bits into an array[TM_NBITS=40, uint8], so bits 38 and 39 are always 0 and
their negations always 1. The kit reports them as constant dead inputs.
Task 2 — the six groups
All functions take a trained TmMachine (or an externally supplied clause set)
plus seq[DiagSample] where DiagSample.lits is the pos-then-neg literal vector
and DiagSample.label the true class.
# build samples from raw bits
let s = makeSample(nBits, rawBits, label, order)
# 1. pre-flight DATA checks
let dc = dataChecks(labels, nClasses, threshold = 0.30)
# dc.classCounts, dc.classShares, dc.majorityClass, dc.majorityShare,
# dc.majorityAccuracy, dc.overThreshold, dc.flags
let sc = shuffledLabelControl(tmplMachine, samples) # (acc, majority, ...)
# 2. clause introspection
let infos = clauseInfo(m, samples, spec)
let summ = clauseSummary(infos) # empty / neverFired / length hist
for c in topClauses(infos, 10): echo c.text, " votes=", c.votes
for cb in clauseBalanceByClass(infos, nClasses): echo cb
for cl in 0..<nClasses: # recover the class rule
echo spec.describeClause(necessaryLiterals(m, samples, cl), cl)
# 3. per-feature contribution + DEAD-INPUT LIST
let contribs = featureContributions(m, samples, spec)
let dead = deadInputs(contribs) # weighted < 5% of top, or never used
let strict = neverUsedInputs(contribs) # appearances == 0
let consts = constantInputs(samples, nBits)
for c in rankedInputs(contribs)[0..<10]: echo c.name, " ", c.weighted
# 4. accuracy diagnostics
let ad = accuracyDiagnostics(m, samples)
# ad.acc, ad.majorityBaseline, ad.margin, ad.confusion,
# ad.perClassRecall/Precision, ad.predMajorityShare
# 5. learning curve
let lc = learningCurve(tmplMachine, train, eval, nPoints = 10)
# lc.points, lc.accs, lc.trend ("flat" | "rising" | "rising-then-falling ...")
# 6. ablation hooks
let base = ablateBaseline(tmplMachine, train, eval)
for r in ablateDropAllBlocks(tmplMachine, train, eval, spec): echo r.name, r.delta
let rs = ablateScrambleFeature(tmplMachine, train, eval, spec, bit)
ablation retrains a fresh machine per variant (the strongest form of "does this
input earn its bits"). Pass baselineAcc from ablateBaseline to avoid
recomputing it per block.
The default-off real-gun hook
guns/tm_pattern.nim gained only additive, default-off instrumentation:
g.diagCapture = true # default false; no behaviour change when false
# ... replay ...
g.diagSamples # seq[TmDiagSample] (literal vector + label)
g.exportTeams() # read-only GF clause teams
g.exportRadTeams(); g.exportRevTeams()
To introspect an externally trained clause set:
let m = machineFromTeams(TM_NBITS, TM_CLASSES, TM_NCLAUSES, TM_NSTATES, TM_S,
g.exportTeams())
Running the demos / tests
nim c -r -d:release --path:common_libs common_libs/tests/test_tm_diag.nim # 48 pure unit checks
nim c -r -d:release --path:common_libs common_libs/tests/diag_synthetic.nim # Task 3 proof
nim c -r -d:release --path:common_libs common_libs/tests/diag_tm_pattern_offline.nim # Task 4 real reading
See common_libs/tests/diag_synthetic.nim for the ground-truth validation and
common_libs/tests/diag_tm_pattern_offline.nim for the real reading.