TAO VCN Classify Gap Analysis Skill

You are an analyst for NVIDIA TAO VCN Classify (Visual Component Net) inference results. Your job is to identify the weakest samples per ground-truth label by measuring signed distance from the decision threshold in the wrong direction, then surface them for downstream augmentation or relabeling.

This skill is intentionally lightweight. VCN's classify head is a single-score binary boundary (PASS vs NO_PASS by

siamese_score

), so the analysis is computational, not investigative. The whole computation lives behind one direct

docker run

invocation against the

tao_toolkit.data_services

image declared in

versions.yaml

(resolved at runtime — see Setup). The container's entrypoint takes

<category> <action> [hydra overrides...]

; we pass

gap_analysis vcn_aoi key=value …

. You do not need subagents, multi-phase image audits, or component-type clustering — VCN does not expose those dimensions. View only a small set of representative weak samples to qualify the gaps after the container returns.

The CLI surface can shift between data-services container builds. If a

gap_analysis vcn_aoi

invocation fails on argument parsing, introspect the actual schema once per image with

docker run --rm "$DS_IMAGE" gap_analysis vcn_aoi --cfg=job

and reconcile any renamed keys before retrying. See

references/troubleshooting.md

for the key-rename reconciliation and the full pitfalls list. The output parquet name is

kpi_gaps.parquet

Inputs

Experiment result directory — contains
```
inference/inference.csv
```
(required columns
```
input_path
```
,
```
object_name
```
,
```
label
```
,
```
siamese_score
```
). Pass the directory (e.g.
```
inference/latest/
```
), not the CSV file.
Training code/config directory — contains the VCN train YAML; the container reads
```
dataset.classify.input_map
```
and
```
dataset.classify.image_ext
```
for per-lighting expansion.
Dataset directory — image root (
```
kpi_media_path
```
) prepended to each row's relative
```
input_path
```
.
Schema overrides —
```
min_recall
```
,
```
top_k_per_label
```
, and optionally a hard-pinned
```
threshold
```
, passed as Hydra overrides (defaults:
```
min_recall=1.0
```
,
```
top_k_per_label=50
```
,
```
threshold=-1.0
```
meaning sweep). top_k_per_label
must be a positive integer — omitting it flips the container into "below-threshold filter" mode, which at
```
min_recall=1.0
```
returns only PASS misclassifications and zero NO_PASS rows.

See

references/parameters-and-artifacts.md

for the full input detail, the

GapAnalysisConfig

override semantics, and the per-default explanation.

Setup

The threshold sweep, weakness ranking, and per-lighting expansion all run inside the

tao_toolkit.data_services

image declared in

versions.yaml

. Resolve the concrete URI once at the top of the run, then confirm Docker, the NVIDIA container toolkit, and a GPU are present and ensure the image is cached:

bash

# Resolve tao_toolkit.data_services → concrete nvcr.io/... URI from versions.yaml
DS_IMAGE=$(python3 -c "import yaml,os; print(yaml.safe_load(open(os.environ['TAO_SKILL_BANK_PATH']+'/versions.yaml'))['images']['tao_toolkit']['data_services'])")
echo "DS_IMAGE=$DS_IMAGE"

docker info > /dev/null && echo "OK: docker"
nvidia-smi > /dev/null && echo "OK: GPU"
docker image inspect "$DS_IMAGE" > /dev/null \
  || docker pull "$DS_IMAGE"

TAO_SKILL_BANK_PATH

is exported by the plugin's

session_start

hook. If it is unset (e.g. running outside the Claude Code plugin), point it at the skill-bank repo root before resolving.

A GPU is required (the same image is used across the AOI loop and other actions assume CUDA is present). Aborting early on a GPU-less host saves a confusing late error.

Path mounting. Every host path the container reads or writes —

inference.csv

, the train YAML, the dataset image root, and the output dir — must be bind-mounted. The simplest pattern is to mount the workspace root with identical paths inside and outside the container so absolute paths in args resolve the same on both sides:

bash

WORKSPACE=<absolute path that contains inference.csv, train YAML, dataset images, and the output dir>
DOCKER="docker run --gpus all --rm --ipc=host --user $(id -u):$(id -g) -v $WORKSPACE:$WORKSPACE -w $WORKSPACE $DS_IMAGE"

inference.csv

, the train YAML, and the dataset images live in different roots, pass multiple

-v

flags — but every absolute path you pass in args must resolve inside the container.

CLI overrides cover the common case.

min_recall

top_k_per_label

, and optionally

threshold

are passed as Hydra overrides on the command line; defaults baked into the container (

min_recall=1.0

top_k_per_label=50

threshold=-1.0

to sweep) handle most runs. If the container also accepts a spec file via

-e <spec>

(verify with

--cfg=job

), passing one is a convenience, not a requirement — override only what you need.

Method

The whole skill is a single

docker run

invocation followed by a small visual spot-check. The container does Steps 1–4 internally (threshold sweep, weakness scoring, top-K selection, per-lighting expansion). You handle Step 5 (visual spot-check) directly with the Read tool.

Step 1–4 — Run the container

bash

$DOCKER gap_analysis vcn_aoi \
    inference_results_dir=<exp_dir>/inference/<label>/ \
    train_config=<exp_dir>/train.yaml \
    kpi_media_path=<dataset_root> \
    results_dir=<rca_results_dir> \
    top_k_per_label=50

Always pass
top_k_per_label
. This is the argument that switches the container from the default "samples below threshold" filter into proper top-K-per-label ranking. At
min_recall=1.0
the threshold is by construction at-or-below every NO_PASS score, so the below-threshold filter returns ONLY misclassified PASS rows and zero NO_PASS rows — useless as an augmentation queue. With
top_k_per_label
set to a positive integer (either in the spec or as a Hydra override), the container computes signed weakness against the threshold for every row and surfaces the K weakest per ground-truth label, which is the per-label ranked output downstream steps consume.

The container sweeps every unique

siamese_score

(plus one value just below the minimum), keeps candidates with NO_PASS recall ≥

min_recall

(tolerance

1e-12

), picks the best-F1 threshold (tie-break: precision, then threshold value), scores signed weakness per row, takes the top

top_k_per_label

per ground-truth label, and expands each into one row per lighting. See

references/parameters-and-artifacts.md

for the exact computation, the override defaults, and the artifact table.

If no candidate threshold meets the recall target, the container exits non-zero and writes

unreachable_kpi.txt

into

results_dir

explaining which recall the model can actually achieve. In that case, stop the analysis after the docker call, write a one-section report explaining the model fundamentally cannot reach the KPI at any operating point, and recommend retraining or relabeling — skip the visual spot-check.

Container writes into
results_dir
:

kpi_gaps.parquet

(top-K weakest per label, expanded per lighting; columns

filepath

label

siamese_score

weakness

threshold.txt

metrics.json

weak_samples_breakdown.txt

, and

unreachable_kpi.txt

(only when the recall target is unreachable). See

references/parameters-and-artifacts.md

for the per-artifact contents. Print the container's stdout summary (chosen threshold, kept-row counts, per-label breakdown) to your own stdout so the script-check hook can verify the run produced output.

Step 5 — Visual spot check (small, fixed)

Skip this step if

unreachable_kpi.txt

exists in

results_dir

— there is nothing meaningful to spot-check when the model can't reach the KPI at any threshold.

Otherwise, use the Read tool to view the test images for:

The 5 weakest PASS samples (the top of the "PASS misclassified as NO_PASS" pile) — pick by sorting
```
kpi_gaps.parquet
```
rows where
```
label == 'PASS'
```
by
```
weakness
```
descending.
The 5 weakest NO_PASS samples (the top of the "NO_PASS misclassified as PASS" pile) — same, with
```
label != 'PASS'
```
.

kpi_gaps.parquet

is already expanded per-lighting (multiple rows per sample). For the spot check, deduplicate to one row per (input_path, object_name) — pick the row whose

filepath

uses the FIRST lighting from the train YAML (one image per sample is enough — VCN's classify head sees all lightings stacked, but for human spot-check one is representative).

Classify each viewed sample as exactly one of:

mislabeled — visual content disagrees with the CSV label
edge case — genuinely ambiguous boundary case
data quality — corrupted, dark, wrong crop, bad framing
systematic — model has learned the wrong feature (the image looks "obviously PASS/NO_PASS" but the model disagrees)

Copy each viewed image (resized to 128×128 if PIL is available, otherwise just copy) into

<results_dir>/rca_images/

so it can be embedded inline in the report.

This is the only image inspection required. Do not view dozens of images, do not run failure mode clustering, do not audit goldens — VCN does not have golden images.

Reference invocation

The paste-and-edit end-to-end recipe (workspace, four paths, two numeric knobs, spec-file write, docker run, and the stdout sanity print that surfaces row counts for the script-check hook) lives in

references/recipe.md

. Use it verbatim, editing only the workspace, paths, and knobs.

Outputs

Write everything into a timestamped folder under the experiment result directory:

<experiment_result_dir>/rca_results/YYYY-MM-DD_HHMMSS/

. The container's outputs (

kpi_gaps.parquet

threshold.txt

metrics.json

weak_samples_breakdown.txt

, and

unreachable_kpi.txt

when applicable) go straight there; the visual spot-check writes

rca_images/

; the packaging hook adds

rca_config/

and

claude_session.jsonl

automatically when

RCA_Report.md

is written. See

references/parameters-and-artifacts.md

for the full folder tree.

At the start of the run, get the real timestamp by running

date +%Y-%m-%d_%H%M%S

in Bash. Do NOT hardcode or guess. If the user specifies a custom output path, use that instead but maintain the same internal structure.

Common pitfalls

The most consequential failure is forgetting
top_k_per_label
when
min_recall=1.0
— at that recall the chosen threshold sits at or below every NO_PASS score, so the fallback below-threshold filter matches ONLY misclassified PASS rows and

kpi_gaps.parquet

ends up with zero NO_PASS rows. Always include an explicit positive

top_k_per_label

. The full pitfalls list (spec file outside

$WORKSPACE

, unresolved

???

sentinels, wrong/unpulled image tag, path-mount mismatch,

unreachable_kpi.txt

handling, missing

inference.csv

columns, missing train-YAML keys,

kpi_media_path

prefix mismatch, no GPU inside the container) and the CLI-drift reconciliation are in

references/troubleshooting.md

Report Structure

Write the RCA report into the timestamped output folder. It is a 7-section computational gap analysis (Verdict, Threshold Selection, Weakness Distribution, Top-K Weakest Samples, Visual Spot Check, Per-Label Breakdown, Recommended Actions), 1000–1800 words, with the confusion-matrix and per-label tables filled from

metrics.json

and the spot-check rows from

kpi_gaps.parquet

. When

unreachable_kpi.txt

exists, replace sections 3–6 with one short section quoting that file and collapse section 7 to a single retrain-or-relabel recommendation. See

references/rca-report-structure.md

for the complete skeleton with every section heading, table layout, and the unreachable-KPI variant.

Execution Order

Resolve
```
DS_IMAGE
```
from
```
versions.yaml
```
(
```
images.tao_toolkit.data_services
```
), then run
```
docker info
```
,
```
nvidia-smi
```
, and
```
docker image inspect "$DS_IMAGE"
```
(pulling if missing) once to confirm the environment. Abort with a clear message if any fail.

Run

date +%Y-%m-%d_%H%M%S

to get the timestamp; create

<experiment_result_dir>/rca_results/<timestamp>/

Write
```
vcn_aoi_spec.yaml
```
into the timestamped dir with
```
min_recall
```
and
```
top_k_per_label
```
filled in. Keep it under
```
$WORKSPACE
```
so the
```
-e
```
path resolves inside the container.

Run

docker run … "$DS_IMAGE" gap_analysis vcn_aoi -e vcn_aoi_spec.yaml inference_results_dir=… train_config=… kpi_media_path=… output_dir=…

. The container writes

kpi_gaps.parquet

threshold.txt

metrics.json

weak_samples_breakdown.txt

into

results_dir

. Print the chosen threshold and kept-row counts to stdout so the script-check hook can verify the run produced output.

If
```
unreachable_kpi.txt
```
exists, skip Step 6 and write the abridged report. Otherwise continue.
Pick 10 weak samples (5 weakest PASS + 5 weakest NO_PASS) from
```
kpi_gaps.parquet
```
, view each test image with Read, classify, and copy each into
```
rca_images/
```
.
Write
```
RCA_Report.md
```
last — writing it triggers the packaging hook, which copies session logs and skill config alongside.

tao-analyze-gaps-visual-changenet

NPX Install

Tags

SKILL.md Content

TAO VCN Classify Gap Analysis Skill

Inputs

Setup

Method

Step 1–4 — Run the container

Step 5 — Visual spot check (small, fixed)

Reference invocation

Outputs

Common pitfalls

Report Structure

Execution Order