Add POIs and journey times to map

This commit is contained in:
Andras Schmelczer 2026-01-28 22:10:41 +00:00
parent 7bfb1729bf
commit 500b9ef2aa
11 changed files with 914 additions and 177 deletions

View file

@ -6,31 +6,47 @@ import polars as pl
from pipeline.config import AGGREGATES_DIR, H3_RESOLUTIONS, PROCESSED_DIR
JOURNEY_COLS = [
"public_transport_easy_minutes",
"public_transport_quick_minutes",
"cycling_minutes",
]
AGGREGATE_COLS = [
"median_pt_easy_minutes",
"median_pt_quick_minutes",
"median_cycling_minutes",
"median_journey_minutes",
]
def aggregate_journey_times(
journey_times_path: Path | None = None,
postcodes_h3_path: Path | None = None,
output_dir: Path | None = None,
aggregates_dir: Path | None = None,
) -> list[Path]:
"""
Aggregate journey times by H3 cells at all resolutions.
Add journey times to existing H3 aggregate parquet files.
Joins journey_times_bank.parquet with postcodes_h3.parquet on postcode,
then groups by H3 cell to compute median journey time.
Joins journey_times_bank_checkpoint.parquet with postcodes_h3.parquet on postcode,
aggregates by H3 cell, then merges into existing res{N}.parquet files.
"""
journey_times_path = journey_times_path or PROCESSED_DIR / "journey_times_bank.parquet"
journey_times_path = (
journey_times_path
or PROCESSED_DIR / "journey_times_bank_checkpoint.parquet"
)
postcodes_h3_path = postcodes_h3_path or PROCESSED_DIR / "postcodes_h3.parquet"
output_dir = output_dir or AGGREGATES_DIR
output_dir.mkdir(parents=True, exist_ok=True)
aggregates_dir = aggregates_dir or AGGREGATES_DIR
# Load journey times data
journey_df = pl.read_parquet(journey_times_path).select(
["postcode", "public_transport_minutes"]
["postcode"] + JOURNEY_COLS
)
# Filter out null journey times
journey_df = journey_df.filter(pl.col("public_transport_minutes").is_not_null())
# Filter out rows where all journey time columns are null
journey_df = journey_df.filter(
pl.any_horizontal(pl.col(c).is_not_null() for c in JOURNEY_COLS)
)
if journey_df.height == 0:
print("No valid journey times found")
@ -48,31 +64,63 @@ def aggregate_journey_times(
print(f"Joined {joined_df.height} postcodes with journey times")
saved_paths = []
updated_paths = []
for resolution in H3_RESOLUTIONS:
h3_col = f"h3_res{resolution}"
parquet_path = aggregates_dir / f"res{resolution}.parquet"
if not parquet_path.exists():
print(f"Skipping resolution {resolution} - {parquet_path} not found")
continue
if h3_col not in joined_df.columns:
print(f"Skipping resolution {resolution} - column {h3_col} not found")
continue
# Aggregate by H3 cell - compute median journey time
agg_df = (
# Aggregate journey times by H3 cell
journey_agg = (
joined_df.group_by(h3_col)
.agg(
pl.col("public_transport_minutes").median().alias("median_journey_minutes"),
pl.col("public_transport_minutes").count().alias("journey_count"),
pl.col("public_transport_easy_minutes")
.median()
.alias("median_pt_easy_minutes"),
pl.col("public_transport_quick_minutes")
.median()
.alias("median_pt_quick_minutes"),
pl.col("cycling_minutes")
.median()
.alias("median_cycling_minutes"),
pl.col("public_transport_quick_minutes")
.median()
.alias("median_journey_minutes"),
)
.rename({h3_col: "h3"})
)
output_path = output_dir / f"journey_times_res{resolution}.parquet"
agg_df.write_parquet(output_path)
saved_paths.append(output_path)
print(f"Saved {agg_df.height} cells to {output_path}")
# Load existing parquet
existing_df = pl.read_parquet(parquet_path)
return saved_paths
# Drop existing journey time columns if present
existing_df = existing_df.drop(
[c for c in AGGREGATE_COLS if c in existing_df.columns]
)
# Left join journey times onto existing data
updated_df = existing_df.join(journey_agg, on="h3", how="left")
# Save back to parquet
updated_df.write_parquet(parquet_path)
updated_paths.append(parquet_path)
matched = updated_df.filter(
pl.col("median_journey_minutes").is_not_null()
).height
print(
f"Updated {parquet_path.name}: {matched} rows with journey times "
f"(out of {updated_df.height} total)"
)
return updated_paths
if __name__ == "__main__":