Strange results from ox.consolidate_intersectons

[davidmurray]

• [x] I have read the OSMnx contributing guidelines
• [x] I have read the OSMnx documentation and usage examples
• [x] I have searched the open/closed issues and StackOverflow for problems similar to mine

Problem description

• What did you do? Tried to use the consolidate_intersections to merge intersection nodes to a single point
• What did you expect to happen? See images below
• And what actually happened instead? See images below

Environment information

• What operating system are you using? macOS
• What Python version are you using? 3.9
• What OSMnx version are you using? 1.3.0
• Provide a complete list of your environment's packages and their versions (for example, run conda list or pip list then paste the output between the two "details" tags below)

Package Version Editable project location ------------------------ ------------ ------------------------------------------- adjustText 0.7.3 affine 2.3.1 aiohttp 3.8.1 aiohttp-cors 0.7.0 aiosignal 1.2.0 anyio 3.6.2 appnope 0.1.3 argon2-cffi 21.3.0 argon2-cffi-bindings 21.2.0 asttokens 2.0.5 async-timeout 4.0.2 attrs 21.4.0 backcall 0.2.0 beautifulsoup4 4.11.1 bleach 5.0.1 blessed 1.19.1 boto3 1.24.77 botocore 1.27.77 branca 0.5.0 cachetools 5.2.0 certifi 2022.6.15 cffi 1.15.1 charset-normalizer 2.1.0 click 8.1.3 click-plugins 1.1.1 cligj 0.7.2 cloudpickle 2.2.0 colorful 0.5.4 contextily 1.2.0 cycler 0.11.0 Cython 0.29.32 cytoolz 0.12.0 dask 2022.1.1 deap 1.3.3 debugpy 1.6.2 decorator 5.1.1 defusedxml 0.7.1 distlib 0.3.6 distributed 2022.1.1 entrypoints 0.4 et-xmlfile 1.1.0 executing 0.8.3 fastjsonschema 2.16.1 filelock 3.8.0 Fiona 1.8.21 folium 0.12.1.post1 fonttools 4.34.4 frozenlist 1.3.0 fsspec 2022.8.2 GDAL 3.5.1 geographiclib 1.52 geopandas 0.12.2 geopy 2.2.0 geotiler 0.14.6 google-api-core 2.10.1 google-auth 2.11.1 googleapis-common-protos 1.56.4 gpustat 1.0.0 grpcio 1.43.0 HeapDict 1.0.1 idna 3.3 ipykernel 6.15.1 ipyleaflet 0.17.1 ipympl 0.9.2 ipython 8.4.0 ipython-genutils 0.2.0 ipywidgets 7.7.1 jedi 0.18.1 Jinja2 3.1.2 jmespath 1.0.1 joblib 1.1.0 jsonschema 4.7.2 jupyter 1.0.0 jupyter-client 7.3.4 jupyter-console 6.4.4 jupyter-core 4.11.1 jupyter-server 1.23.3 jupyterlab-execute-time 2.3.0 jupyterlab-pygments 0.2.2 jupyterlab-widgets 1.1.1 kiwisolver 1.4.4 line-profiler 4.0.1 locket 1.0.0 lxml 4.9.1 MarkupSafe 2.1.1 matplotlib 3.5.2 matplotlib-inline 0.1.3 mercantile 1.2.1 mistune 0.8.4 modin-spreadsheet 0.1.2 msgpack 1.0.4 multidict 6.0.2 munch 2.5.0 nbclient 0.6.6 nbconvert 6.5.0 nbformat 5.4.0 nest-asyncio 1.5.5 networkx 2.8.5 notebook 6.4.12 numpy 1.23.1 nvidia-ml-py 11.495.46 opencensus 0.11.0 opencensus-context 0.1.3 openpyxl 3.0.10 osmnx 1.3.0 packaging 21.3 pandas 1.5.2 pandocfilters 1.5.0 parso 0.8.3 partd 1.3.0 pexpect 4.8.0 pickleshare 0.7.5 Pillow 9.2.0 pip 22.1.1 pip-autoremove 0.10.0 platformdirs 2.5.2 plotly 5.9.0 plumbum 1.7.2 polyline 1.4.0 prometheus-client 0.13.1 prompt-toolkit 3.0.30 protobuf 3.20.2 psutil 5.9.1 ptyprocess 0.7.0 pure-eval 0.2.2 py-spy 0.3.14 pyarrow 9.0.0 pyasn1 0.4.8 pyasn1-modules 0.2.8 pycparser 2.21 pygad 2.17.0 Pygments 2.12.0 pyinstrument 4.3.0 pyparsing 3.0.9 pyproj 3.4.1 pyrsistent 0.18.1 pyshp 2.3.1 python-dateutil 2.8.2 pytz 2022.1 PyYAML 6.0 pyzmq 23.2.0 qtconsole 5.3.2 QtPy 2.2.0 rasterio 1.3.2 ray 1.12.1 redis 3.5.3 requests 2.28.1 rpyc 4.1.5 rsa 4.9 Rtree 1.0.0 s3transfer 0.6.0 scipy 1.9.1 Send2Trash 1.8.0 setuptools 62.3.2 shapely 2.0.0 six 1.16.0 smart-open 6.2.0 sniffio 1.3.0 snuggs 1.4.7 sortedcontainers 2.4.0 soupsieve 2.3.2.post1 stack-data 0.3.0 swifter 1.3.4 tblib 1.7.0 tenacity 8.0.1 terminado 0.15.0 tinycss2 1.1.1 toolz 0.12.0 tornado 6.2 tqdm 4.64.0 traitlets 5.3.0 traittypes 0.2.1 ujson 5.6.0 urllib3 1.26.10 utilities 1.0 virtualenv 20.16.5 wcwidth 0.2.5 webencodings 0.5.1 websocket-client 1.4.2 widgetsnbextension 3.6.1 xyzservices 2022.6.0 yappi 1.4.0 yarl 1.7.2 zict 2.2.0

Provide a complete minimal reproducible example

## Complete minimal example
import osmnx as ox

if "all_private" not in ox.settings.bidirectional_network_types:
    ox.settings.bidirectional_network_types.append('all_private')

G = ox.graph_from_xml(os.path.join(PROJECT_ROOT, "osm", "algo", "osm_network_agglomeration_montreal.xml"),
                               simplify=False,
                               retain_all=True,
                               bidirectional=True) # We want bidirectional edges, even for one-way streets.

# Project the graph to meters
G = ox.project_graph(G, to_crs='epsg:2950')

# Filter edges based on highway type
allowed_highway_types = ["primary", 
                         "secondary", 
                         "tertiary", 
                        ]
edges_subset = []
for u, v, data in G.edges(data=True):
    if data['highway'] in allowed_highway_types:
        edges_subset.append((u, v, 0))

G_subset = G.edge_subgraph(edges_subset)
gdf_links_raw = ox.graph_to_gdfs(G_subset, nodes=False)

G_consolidated = ox.consolidate_intersections(G_subset, rebuild_graph=True, tolerance=15, dead_ends=False)
gdf_links_consolidated = ox.graph_to_gdfs(G_consolidated, nodes=False)

# Then plot those graphs using folium for example

Unconsolidated intersections:

Consolidated intersections:

Question: why isn't it merged like this?

Note: I tried changing the tolerance to 10m and 20m but I never seem to get the intended result. Perhaps I am misunderstanding the results that consolidate_intersections should offer. Note: The OSM XML file is attached, but it's basically just an export of highway=* from Overpass.

Here is the intersection in OpenStreetMap: https://www.openstreetmap.org/#map=18/45.55885/-73.59832

Thanks! osm_network_agglomeration_montreal.xml.zip

[gboeing]

Please provide the OSM IDs of the nodes that were merged together into this single consolidated node, and which of them you believe should not have been merged.

[davidmurray]

Hi, I think I had misunderstood the "tolerance" parameter and accidentally set it larger than it had to be, thus merging nodes that shouldn't be merged. Closing this issue :)