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Is This Telescope Flash a Gamma Ray?

Did this flash of light in the telescope come from a gamma ray or from ordinary cosmic-ray noise? Telling them apart quickly is how a ground telescope finds the rare gamma-ray sources it's built to study.

Use caseSciencePredictionModel evaluation

The table

Simulated flashes recorded by the MAGIC telescope, each described by ten shape measurements of its image, labelled gamma or hadron. It's in Welt's research catalogue as MAGIC Gamma Telescope, 19,020 rows by 11 columns, licensed CC BY 4.0. The catalogue measures its signal at 0.66. At 19,020 rows and 10 features the table is larger than the model limits allow, so the walkthrough evaluates and fits on a seeded sample of 8,000 rows. TabICLv2 and Kumo Tabular Medium compete.

Walkthrough

  1. Load it from the catalogue

    Find the table, read its recorded target and print the column names.

    import pandas as pd
    from welt import Client
    
    with Client() as client:
        item = client.research_datasets(q="MAGIC gamma telescope", limit=1)["items"][0]
        info = client.research_dataset(item["id"])
        data = client.load_research_dataset(item["id"])
    
    target = info["targets"][0]
    target = target["name"] if isinstance(target, dict) else target
    print([column["name"] for column in info["schema"]], target)
  2. Pick the rows

    Set aside 20 rows to predict at the end. The models learn from a seeded sample of 8,000 of the rest, the most this table's width allows.

    known = data.dropna(subset=[target])
    new_rows = known.sample(20, random_state=1)
    table = known.drop(new_rows.index).sample(8000, random_state=7)
  3. Compare the models and predict

    The models compete on the same folds against a simple guess, then the top-ranked one is fitted on the whole table. ROC AUC runs from 0.5, a coin toss, to 1, a perfect ranking, and a lower Brier score means the probabilities can be trusted more. The last table puts each prediction next to the real answer.

    with Client() as client:
        evaluation = client.evaluate(table, target, task="classification", seed=7,
                                     models=["tabicl-v2", "kumo-medium"])
        model = evaluation.fit()
    
    print(evaluation.summary()[["name", "rank", "roc_auc_mean", "brier_mean"]])
    features = new_rows.drop(columns=target)
    print(pd.DataFrame({"actual": new_rows[target].values, "predicted": model.predict(features),
                        "probability": model.predict_proba(features).max(axis=1)}))

What you get

A probability per flashRank events by how likely each is to be a gamma ray.
Cleaner signalThrow away the background before any deeper analysis.
A known benchmarkCompare the result with years of published work on this table.

Try it

Use Open with to run the research datasets notebook in Colab, Kaggle or Jupyter and search for "MAGIC gamma telescope", or run the code above after pip install "welt-client[parquet]".