dd-l1-london-parks-count
Map (reference ← swipe → agent)
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I've got inner-London parks (london_parks) and I'm sizing the corpus before commissioning a green-space accessibility study. How many of those parks come in at one hectare or more, what's their combined area in hectares, and what bounding box would I draw around that subset on a WGS84 map? Output parks_summary.json with keys count, total_area_ha, and bbox_wgs84 (as a [xmin, ymin, xmax, ymax] array).
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System info
{
"adapter": "openrouter",
"model": "google/gemma-4-26b-a4b-it",
"base_url": "https://openrouter.ai/api/v1"
}
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Bash
ls -F
ls -F
london_parks.fgb
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Write
/work/solve.py
content · 56 lines · py
import geopandas as gpd
import json
def main():
# Load the parks data
gdf = gpd.read_file('london_parks.fgb')
# The input is likely in a projected CRS (e.g., EPSG:27700 for UK).
# We need to ensure we can calculate area in square meters/hectares accurately.
# Let's check the current CRS.
print(f"Original CRS: {gdf.crs}")
# Filter parks that are 1 hectare or more.
# 1 hectare = 10,000 square meters.
# First, ensure we are in a projected CRS to calculate area correctly.
# If it's already projected, great. If not, we'll reproject to EPSG:27700.
if gdf.crs is None or gdf.crs.is_geographic:
gdf_projected = gdf.to_crs(epsg=27700)
else:
gdf_projected = gdf.copy()
# Calculate area in hectares (1 ha = 10,000 m^2)
gdf_projected['area_ha'] = gdf_projected.geometry.area / 10000.0
# Filter subset
subset = gdf_projected[gdf_projected['area_ha'] >= 1.0].copy()
# Calculate summary statistics
count = len(subset)
total_area_ha = subset['area_ha'].sum()
# Calculate bounding box in WGS84 (EPSG:4326)
if count > 0:
subset_wgs84 = subset.to_crs(epsg=4326)
bounds = subset_wgs84.total_bounds # [xmin, ymin, xmax, ymax]
bbox_wgs84 = bounds.tolist()
else:
bbox_wgs84 = []
# Prepare output
summary = {
"count": int(count),
"total_area_ha": float(total_area_ha),
"bbox_wgs84": bbox_wgs84
}
# Write to JSON
with open('parks_summary.json', 'w') as f:
json.dump(summary, f, indent=4)
print("Summary calculation complete.")
print(summary)
if __name__ == "__main__":
main()
Wrote /work/solve.py (1677 chars).
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Bash
python solve.py
python solve.py
Original CRS: EPSG:27700
Summary calculation complete.
{'count': 42, 'total_area_ha': 519.1620805430861, 'bbox_wgs84': [-0.19932378751294652, 51.49147199538401, -0.08248178747996572, 51.54706589542573]}
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