geo-l1-cairo-multipoint-hull
Map (reference ← swipe → agent)
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I'm putting together the accessibility report for the Metro, and its static maps need to show how far each station's underground box reaches at street level. `cairo_metro_stations.geojson` has each station's street-level entrances. Can you compute the convex hull of each station's entrances and save the result to `cairo_metro_hulls.geojson`, one Polygon per station? Every row must carry `station_name_en` and `station_name_ar`, both non-empty, with the original Arabic strings and diacritics preserved exactly as they appear in the input.
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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
cairo_metro_stations.geojson
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Read
cairo_metro_stations.geojson
1 {
2 "type": "FeatureCollection",
3 "name": "cairo_metro_stations",
4 "crs": { "type": "name", "properties": { "name": "urn:ogc:def:crs:OGC:1.3:CRS84" } },
5 "features": [
6 { "type": "Feature", "properties": { "station_name_en": "Al-Shohadaa", "station_name_ar": "الشهداء" }, "geometry": { "type": "MultiPoint", "coordinates": [ [ 31.246441, 30.063109 ], [ 31.246778, 30.062428 ], [ 31.246859, 30.063158 ], [ 31.247736, 30.061538 ], [ 31.247931, 30.062636 ] ] } },
7 { "type": "Feature", "properties": { "station_name_en": "Attaba", "station_name_ar": "العتبة" }, "geometry": { "type": "MultiPoint", "coordinates": [ [ 31.246196, 30.051508 ], [ 31.246396, 30.051849 ], [ 31.246716, 30.051944 ], [ 31.246936, 30.052384 ], [ 31.247559, 30.052018 ] ] } },
8 { "type": "Feature", "properties": { "station_name_en": "Cairo University", "station_name_ar": "جامعة القاهرة" }, "geometry": { "type": "MultiPoint", "coordinates": [ [ 31.200216, 30.025256 ], [ 31.200826, 30.026512 ], [ 31.201257, 30.02592 ], [ 31.201463, 30.025147 ], [ 31.20167, 30.026648 ] ] } },
9 { "type": "Feature", "properties": { "station_name_en": "Dokki", "station_name_ar": "الدقي" }, "geometry": { "type": "MultiPoint", "coordinates": [ [ 31.211926, 30.038446 ], [ 31.212858, 30.038563 ], [ 31.213071, 30.039014 ], [ 31.213408, 30.037575 ] ] } },
10 { "type": "Feature", "properties": { "station_name_en": "El Demerdash", "station_name_ar": "الدمرداش" }, "geometry": { "type": "MultiPoint", "coordinates": [ [ 31.272726, 30.079096 ], [ 31.272841, 30.079167 ], [ 31.273817, 30.078925 ], [ 31.274032, 30.079479 ] ] } },
<system-reminder>Showed lines 1-10 of 27. Re-call Read with offset=11 to continue, or raise limit.</system-reminder>
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Write
solve.py
content · 51 lines · py
import geopandas as gpd
def solve():
# Load the input file
input_file = 'cairo_metro_stations.geojson'
output_file = 'cairo_metro_hulls.geojson'
gdf = gpd.read_file(input_file)
# Check if geometries are valid for convex hull computation
# The input contains MultiPoint geometries representing entrances
# We want the convex hull of these points for each station
# Create a new GeoDataFrame for the hulls
hulls = []
for _, row in gdf.iterrows():
geom = row['geometry']
# Compute the convex hull
# If the geometry is empty or has too few points, convex_hull might return a Point or LineString
# but the requirement asks for a Polygon.
hull_geom = geom.convex_hull
# We should ensure we only keep valid Polygons if possible,
# but for the sake of the task, we take the convex hull.
# If geom is a MultiPoint, convex_hull returns a Polygon.
new_row = row.copy()
new_row['geometry'] = hull_geom
hulls.append(new_row)
hulls_gdf = gpd.GeoDataFrame(hulls, crs=gdf.crs)
# Ensure station names are preserved and non-empty as per requirement
# The input already has them. We just need to make sure we don't drop them.
# The requirement says "Every row must carry station_name_en and station_name_ar, both non-empty"
# Let's filter out any that might be empty just in case, although the prompt implies they are there.
hulls_gdf = hulls_gdf[
(hulls_gdf['station_name_en'].notna()) & (hulls_gdf['station_name_en'].astype(str).str.strip() != "") &
(hulls_gdf['station_name_ar'].notna()) & (hulls_gdf['station_name_ar'].astype(str).str.strip() != "")
]
# Save the result
hulls_gdf.to_file(output_file, driver='GeoJSON')
print(f"Successfully saved hulls to {output_file}")
if __name__ == "__main__":
solve()
Wrote solve.py (1949 chars).
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Bash
python solve.py
Successfully saved hulls to cairo_metro_hulls.geojson
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Read
cairo_metro_hulls.geojson
1 {
2 "type": "FeatureCollection",
3 "name": "cairo_metro_hulls",
4 "crs": { "type": "name", "properties": { "name": "urn:ogc:def:crs:OGC:1.3:CRS84" } },
5 "features": [
<system-reminder>Showed lines 1-5 of 27. Re-call Read with offset=6 to continue, or raise limit.</system-reminder>
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Read
cairo_metro_hulls.geojson
1 {
2 "type": "FeatureCollection",
3 "name": "cairo_metro_hulls",
4 "crs": { "type": "name", "properties": { "name": "urn:ogc:def:crs:OGC:1.3:CRS84" } },
5 "features": [
6 { "type": "Feature", "properties": { "station_name_en": "Al-Shohadaa", "station_name_ar": "الشهداء" }, "geometry": { "type": "Polygon", "coordinates": [ [ [ 31.247736, 30.061538 ], [ 31.246778, 30.062428 ], [ 31.246441, 30.063109 ], [ 31.246859, 30.063158 ], [ 31.247931, 30.062636 ], [ 31.247736, 30.061538 ] ] ] } },
7 { "type": "Feature", "properties": { "station_name_en": "Attaba", "station_name_ar": "العتبة" }, "geometry": { "type": "Polygon", "coordinates": [ [ [ 31.246196, 30.051508 ], [ 31.246396, 30.051849 ], [ 31.246936, 30.052384 ], [ 31.247559, 30.052018 ], [ 31.246196, 30.051508 ] ] ] } },
8 { "type": "Feature", "properties": { "station_name_en": "Cairo University", "station_name_ar": "جامعة القاهرة" }, "geometry": { "type": "Polygon", "coordinates": [ [ [ 31.201463, 30.025147 ], [ 31.200216, 30.025256 ], [ 31.200826, 30.026512 ], [ 31.20167, 30.026648 ], [ 31.201463, 30.025147 ] ] ] } },
9 { "type": "Feature", "properties": { "station_name_en": "Dokki", "station_name_ar": "الدقي" }, "geometry": { "type": "Polygon", "coordinates": [ [ [ 31.213408, 30.037575 ], [ 31.211926, 30.038446 ], [ 31.213071, 30.039014 ], [ 31.213408, 30.037575 ] ] ] } },
10 { "type": "Feature", "properties": { "station_name_en": "El Demerdash", "station_name_ar": "الدمرداش" }, "geometry": { "type": "Polygon", "coordinates": [ [ [ 31.273817, 30.078925 ], [ 31.272726, 30.079096 ], [ 31.272841, 30.079167 ], [ 31.274032, 30.079479 ], [ 31.273817, 30.078925 ] ] ] } },
11 { "type": "Feature", "properties": { "station_name_en": "El Malek El Saleh", "station_name_ar": "الملك الصالح" }, "geometry": { "type": "Polygon", "coordinates": [ [ [ 31.234504, 30.017367 ], [ 31.233473, 30.018682 ], [ 31.233442, 30.019095 ], [ 31.234545, 30.017379 ], [ 31.234504, 30.017367 ] ] ] } },
12 { "type": "Feature", "properties": { "station_name_en": "El-Marg", "station_name_ar": "المرج" }, "geometry": { "type": "Polygon", "coordinates": [ [ [ 31.334217, 30.146468 ], [ 31.334253, 30.146538 ], [ 31.334782, 30.146493 ], [ 31.334217, 30.146468 ] ] ] } },
13 { "type": "Feature", "properties": { "station_name_en": "Ghamra", "station_name_ar": "غمرة" }, "geometry": { "type": "Polygon", "coordinates": [ [ [ 31.263197, 30.068259 ], [ 31.263164, 30.068985 ], [ 31.264394, 30.068864 ], [ 31.263197, 30.068259 ] ] ] } },
14 { "type": "Feature", "properties": { "station_name_en": "Hadayek El-Zaitoun", "station_name_ar": "حدائق الزيتون" }, "geometry": { "type": "Polygon", "coordinates": [ [ [ 31.307789, 30.122103 ], [ 31.3063, 30.122913 ], [ 31.30776, 30.123157 ], [ 31.307849, 30.12264 ], [ 31.307789, 30.122103 ] ] ] } },
15 { "type": "Feature", "properties": { "station_name_en": "Helmeyet El-Zaitoun", "station_name_ar": "حلمية الزيتون" }, "geometry": { "type": "Polygon", "coordinates": [ [ [ 31.302815, 30.111791 ], [ 31.302031, 30.11224 ], [ 31.303183, 30.111908 ], [ 31.302815, 30.111791 ] ] ] } },
16 { "type": "Feature", "properties": { "station_name_en": "Helwan", "station_name_ar": "حلوان" }, "geometry": { "type": "Polygon", "coordinates": [ [ [ 31.333401, 29.847533 ], [ 31.333518, 29.84856 ], [ 31.33383, 29.849118 ], [ 31.33423, 29.849025 ], [ 31.333401, 29.847533 ] ] ] } },
17 { "type": "Feature", "properties": { "station_name_en": "Maadi", "station_name_ar": "المعادي" }, "geometry": { "type": "Polygon", "coordinates": [ [ [ 31.25825, 29.959814 ], [ 31.25776, 29.95986 ], [ 31.256977, 29.960391 ], [ 31.256996, 29.961004 ], [ 31.258343, 29.961018 ], [ 31.25825, 29.959814 ] ] ] } },
18 { "type": "Feature", "properties": { "station_name_en": "Manshiet El-Sadr", "station_name_ar": "منشية الصدر" }, "geometry": { "type": "Polygon", "coordinates": [ [ [ 31.287036, 30.078534 ], [ 31.286919, 30.07915 ], [ 31.287853, 30.078947 ], [ 31.287036, 30.078534 ] ] ] } },
19 { "type": "Feature", "properties": { "station_name_en": "Mar Girgis", "station_name_ar": "مار جرجس" }, "geometry": { "type": "Polygon", "coordinates": [ [ [ 31.229596, 30.005582 ], [ 31.230357, 30.006424 ], [ 31.230863, 30.006943 ], [ 31.229596, 30.005582 ] ] ] } },
20 { "type": "Feature", "properties": { "station_name_en": "Mohamed Naguib", "station_name_ar": "محمد نجيب" }, "geometry": { "type": "Polygon", "coordinates": [ [ [ 31.246011, 30.042638 ], [ 31.245937, 30.043448 ], [ 31.246112, 30.043492 ], [ 31.246072, 30.042795 ], [ 31.246011, 30.042638 ] ] ] } },
21 { "type": "Feature", "properties": { "station_name_en": "Nasser", "station_name_ar": "عبد الناصر" }, "geometry": { "type": "Polygon", "coordinates": [ [ [ 31.244356, 30.052241 ], [ 31.243015, 30.052462 ], [ 31.243026, 30.053981 ], [ 31.244365, 30.053045 ], [ 31.244356, 30.052241 ] ] ] } },
22 { "type": "Feature", "properties": { "station_name_en": "Opera", "station_name_ar": "الأوبرا" }, "geometry": { "type": "Polygon", "coordinates": [ [ [ 31.22406, 30.041978 ], [ 31.223629, 30.042483 ], [ 31.224966, 30.042008 ], [ 31.22406, 30.041978 ] ] ] } },
23 { "type": "Feature", "properties": { "station_name_en": "Saad Zaghloul", "station_name_ar": "سعد زغلول" }, "geometry": { "type": "Polygon", "coordinates": [ [ [ 31.248954, 30.037359 ], [ 31.248006, 30.037688 ], [ 31.248884, 30.037798 ], [ 31.248954, 30.037359 ] ] ] } },
24 { "type": "Feature", "properties": { "station_name_en": "Sadat", "station_name_ar": "السادات" }, "geometry": { "type": "Polygon", "coordinates": [ [ [ 31.236357, 30.043795 ], [ 31.235032, 30.043948 ], [ 31.236493, 30.044874 ], [ 31.236357, 30.043795 ] ] ] } },
25 { "type": "Feature", "properties": { "station_name_en": "Sayeda Zeinab", "station_name_ar": "السيدة زينب" }, "geometry": { "type": "Polygon", "coordinates": [ [ [ 31.23933, 30.028708 ], [ 31.238434, 30.030095 ], [ 31.239612, 30.029943 ], [ 31.239711, 30.028807 ], [ 31.23933, 30.028708 ] ] ] } }
26 ]
27 }
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