Unlinkables chart cuts off for high match weights

[RobinL]

We round probability to 5dp, meaning that no match probabilities above about a mw of 17 appear on the chart

Changes needed:

unlinkables.py

def unlinkables_data(linker: Linker) -> list[dict[str, Any]]:
    """Generate data displaying the proportion of records that are "unlinkable"
    for a given splink score threshold and model parameters. These are records that,
    even when compared with themselves, do not contain enough information to confirm
    a match.

    Args:
        linker (Splink): A Splink data linker
    """

    self_link_df = linker._self_link()

    pipeline = CTEPipeline()

    sql = f"""
        select
        round(match_weight, 1) as match_weight,
        match_probability
        from {self_link_df.physical_name}
    """

    pipeline.enqueue_sql(sql, "__splink__df_round_self_link")

    sql = """
        select
        match_weight,
        max(match_probability) as match_probability,
        count(*) / cast( sum(count(*)) over () as float) as prop
        from __splink__df_round_self_link
        group by match_weight
        order by match_weight
    """

    pipeline.enqueue_sql(sql, "__splink__df_unlinkables_proportions")

    sql = """
        select *,
        sum(prop) over(order by match_probability) as cum_prop
        from __splink__df_unlinkables_proportions
        where match_weight < 60
    """
    pipeline.enqueue_sql(sql, "__splink__df_unlinkables_proportions_cumulative")
    data = linker._db_api.sql_pipeline_to_splink_dataframe(pipeline, use_cache=False)

    unlinkables_dict = data.as_record_dict()
    data.drop_table_from_database_and_remove_from_cache()
    return unlinkables_dict

Spec

// ... existing code ...
        "x": {
          "type": "quantitative",
          "axis": {"format": "+f", "title": "Threshold match weight"},
          "field": "match_weight"
        },
// ... existing code ...
        "x": {
          "type": "quantitative",
          "axis": {"format": "+f", "title": "Threshold match weight"},
          "field": "match_weight"
        },
// ... existing code ...```