weltby Ergodic Sign inGet started
All use cases

Is This Email Spam?

From how often certain words and characters appear and how long its runs of capitals are, is this email spam? It's the table generations of spam filters were tested on.

Use caseTechnologyPredictionModel evaluation

The table

4,601 emails with 57 word, character and capital-letter features, labelled spam or not. It's in Welt's research catalogue as Spambase, 4,601 rows by 58 columns, licensed CC BY 4.0. The catalogue measures its signal at 0.90. At 4,601 rows and 57 features the table is larger than the model limits allow, so the walkthrough evaluates and fits on a seeded sample of 2,000 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="spambase", 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 2,000 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(2000, 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 spam probabilityFor each email.
A threshold you chooseTrade missed spam against lost mail using the out-of-fold scores.
A very strong signalThe catalogue measures a high signal.

Try it

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