Articles on geospatial AI, place-aware computing, and spatial analysis by Dr James Williams.https://jwilliams.science/en-gbhttps://jwilliams.science/blog/h3-hierarchy-compaction/https://jwilliams.science/blog/h3-hierarchy-compaction/Learn how H3's hierarchical structure enables multi-resolution analysis, how parent-child relationships work across resolution levels, and how the compactCells and uncompactCells functions reduce redundant spatial representations. Includes interactive browser demos and practical code examples.Tue, 28 Apr 2026 00:00:00 GMTH3 GridsSpatial ComputingJavaScriptMapping & VisualizationTutorialsGISAlgorithmsJ. Williamshttps://jwilliams.science/blog/h3-catchment-analysis/https://jwilliams.science/blog/h3-catchment-analysis/Learn how to use H3's gridDisk, gridRing, and gridDistance functions to model service areas, accessibility zones, and multi-source catchment overlap. Includes interactive browser-based demos with step-by-step code.Sat, 25 Apr 2026 00:00:00 GMTH3 GridsSpatial ComputingJavaScriptMapping & VisualizationTutorialsGISUrban AnalyticsJ. Williamshttps://jwilliams.science/blog/h3-density-mapping-tutorial/https://jwilliams.science/blog/h3-density-mapping-tutorial/Learn how to aggregate point data into hexagonal density maps using H3 and Leaflet. This tutorial covers spatial binning, choropleth colouring, power-scaled colour ramps, and interactive multi-resolution analysis — all running in the browser.Wed, 22 Apr 2026 00:00:00 GMTH3 GridsSpatial ComputingJavaScriptMapping & VisualizationTutorialsGISData VisualizationJ. Williamshttps://jwilliams.science/blog/place-in-llms/https://jwilliams.science/blog/place-in-llms/A reflective piece on how large language models represent place: the difference between spatial and platial knowledge, what LLMs do well (cultural associations, character, narrative), what they get wrong (boundaries, recency, under-represented places), and how to build applications that use this capability honestly.Wed, 15 Apr 2026 00:00:00 GMTLLMAIPlace TheorySpatial ComputingGISJ. Williamshttps://jwilliams.science/blog/python-llm-streaming-api-tutorial/https://jwilliams.science/blog/python-llm-streaming-api-tutorial/A complete guide to consuming streaming LLM APIs in Python. Covers the SSE protocol, async generator patterns with httpx, token counting and cost estimation during streaming, exponential back-off for rate limits, and a production-ready wrapper class for OpenAI-compatible endpoints. Applied to a real document summarisation pipeline.Tue, 14 Apr 2026 00:00:00 GMTPythonLLMAIAPIsAsyncTutorialsProductionJ. Williamshttps://jwilliams.science/blog/rust-wasm-realtime-data-processing/https://jwilliams.science/blog/rust-wasm-realtime-data-processing/A practical tutorial on compiling Rust to WebAssembly using wasm-pack and wasm-bindgen. Covers writing a Rust processing core, exposing functions to JavaScript, running heavy computation off the main thread using Web Workers, and benchmarking the result against a pure-JavaScript baseline. Applied to a real-time sensor data smoothing use case.Wed, 08 Apr 2026 00:00:00 GMTRustWebAssemblyPerformanceJavaScriptTutorialsSystems ProgrammingJ. Williamshttps://jwilliams.science/blog/golang-concurrency-spatial-pipelines/https://jwilliams.science/blog/golang-concurrency-spatial-pipelines/A practical guide to building high-throughput geospatial data pipelines in Go using goroutines, channels, and the fan-out/fan-in pattern. Includes benchmarked code examples processing H3 hexagonal grid cells in parallel, with proper context cancellation and error handling.Sun, 29 Mar 2026 00:00:00 GMTGoConcurrencySpatial ComputingPerformanceTutorialsGISJ. Williamshttps://jwilliams.science/blog/vector-tiles-pmtiles-maplibre/https://jwilliams.science/blog/vector-tiles-pmtiles-maplibre/A practical guide to generating, hosting, and consuming vector tile archives using PMTiles and MapLibre GL JS. Covers creating PMTiles archives from GeoJSON and GeoPackage sources with Tippecanoe, hosting on S3 or GitHub Pages, and building an interactive web map with custom styles, popups, and dynamic layer control.Thu, 26 Mar 2026 00:00:00 GMTMapLibre GL JSVector TilesPMTilesGISWeb MappingJavaScriptSpatial ComputingJ. Williamshttps://jwilliams.science/blog/elasticsearch-geospatial-search/https://jwilliams.science/blog/elasticsearch-geospatial-search/A practical tutorial on Elasticsearch geospatial search covering geo_point field mapping, geo_distance and geo_bounding_box queries, and advanced relevance scoring using function_score with geo_distance decay functions. Includes Python Elasticsearch client examples and a discussion of when to use each query type.Sun, 22 Mar 2026 00:00:00 GMTElasticsearchSearchSpatial ComputingGISTutorialsJ. Williamshttps://jwilliams.science/blog/duckdb-spatial-analytics/https://jwilliams.science/blog/duckdb-spatial-analytics/A practical guide to using DuckDB's spatial extension for geospatial analysis. Covers installing the extension, running ST_Within and ST_Distance queries over large Parquet datasets, integrating with Python and the broader data ecosystem, and comparing the approach to traditional spatial database setups.Sun, 15 Mar 2026 00:00:00 GMTDuckDBSQLSpatial ComputingAnalyticsGISJ. Williamshttps://jwilliams.science/blog/rust-zero-cost-abstractions/https://jwilliams.science/blog/rust-zero-cost-abstractions/An exploration of Rust's zero-cost abstractions applied to geospatial data processing. Covers iterator chains over coordinate arrays, custom trait implementations for spatial types, and how the Rust compiler eliminates abstraction overhead to produce performance equivalent to hand-written C.Sun, 08 Mar 2026 00:00:00 GMTRustPerformanceGISSystems ProgrammingSpatial ComputingJ. Williamshttps://jwilliams.science/blog/fastapi-postgis-geospatial-api/https://jwilliams.science/blog/fastapi-postgis-geospatial-api/A step-by-step guide to building a geospatial REST API using FastAPI, PostGIS, and GeoAlchemy2. Covers database schema design with spatial indexes, ST_DWithin radius search, GeoJSON response serialisation, async database access, and practical endpoint patterns used in production mapping applications.Tue, 03 Mar 2026 00:00:00 GMTPythonFastAPIPostGISGISSpatial ComputingAPITutorialsJ. Williamshttps://jwilliams.science/blog/geon-geospatial-experience-oriented-notation/https://jwilliams.science/blog/geon-geospatial-experience-oriented-notation/GEON (Geospatial Experience-Oriented Notation) is a preprint introducing a new text-based format for encoding places with semantic richness: identity, geometry, purpose, experiential qualities, spatial relationships, and temporal patterns. Evaluated against GeoJSON, GEON achieves 20% fewer tokens while encoding 31% more semantic facts per token.Sun, 22 Feb 2026 00:00:00 GMTGEONLLMsGeospatial DataSpatial IntelligenceUrban ComputingPlace-Based ComputingTechRxivJ. Williamshttps://jwilliams.science/blog/cloud-native-geospatial-geoparquet-stac/https://jwilliams.science/blog/cloud-native-geospatial-geoparquet-stac/An introduction to the cloud-native geospatial stack: GeoParquet for vector data, Cloud Optimized GeoTIFFs (COGs) for raster data, and the SpatioTemporal Asset Catalog (STAC) specification for discovery. Covers practical Python examples using rio-cogeo, pystac-client, and geopandas with GeoParquet.Thu, 19 Feb 2026 00:00:00 GMTCloud-Native GeospatialGISSpatial ComputingData EngineeringPythonRemote SensingJ. Williamshttps://jwilliams.science/blog/islamica-ramadan-companion/https://jwilliams.science/blog/islamica-ramadan-companion/Islamica is a free Progressive Web App with prayer tracking, fasting logs, Qur'an reading progress, and educational modules for daily Islamic practice. All data stored locally for privacy.Sat, 14 Feb 2026 00:00:00 GMTIslamic AppsRamadanWeb DevelopmentPWAEducationJ. Williamshttps://jwilliams.science/blog/geopandas-shapely-spatial-etl/https://jwilliams.science/blog/geopandas-shapely-spatial-etl/A practical guide to building spatial ETL (extract, transform, load) pipelines using GeoPandas and Shapely. Covers reading and writing spatial formats, geometry validation and repair, coordinate reference system management, spatial joins, and outputting clean data to PostGIS or GeoParquet.Thu, 12 Feb 2026 00:00:00 GMTPythonGeoPandasShapelyGISSpatial ComputingData EngineeringTutorialsJ. Williamshttps://jwilliams.science/blog/chora-python-library-launch/https://jwilliams.science/blog/chora-python-library-launch/Introducing Chora, the first Python library to model the human experience of place. Built on rigorous theory from GIScience, cognitive geography, and social physics, Chora provides tools for processing GPS traces, detecting routines, mapping emotions, and understanding places as lived experiences rather than coordinate pairs.Sat, 07 Feb 2026 00:00:00 GMTChoraPythonPyPIGISPlace TheorySpatial ComputingOpen SourceResearch SoftwareJ. Williamshttps://jwilliams.science/blog/spatial-narrative-rust-library/https://jwilliams.science/blog/spatial-narrative-rust-library/Spatial Narrative is a high-performance Rust library for modelling, indexing, and analysing events that unfold across geographic space and chronological time. Built for researchers, digital humanists, and data scientists, it provides spatial indexing, movement analysis, named entity recognition, and multi-format I/O.Thu, 05 Feb 2026 00:00:00 GMTSpatial NarrativeRustcrates.ioSpatiotemporalGISSpatial ComputingOpen SourceResearch SoftwareJ. Williamshttps://jwilliams.science/blog/placeagents-pedestrian-itineraries/https://jwilliams.science/blog/placeagents-pedestrian-itineraries/PlaceAgents is an open-source framework for simulating platial pedestrian flows in urban environments. Using OpenStreetMap data, H3 spatial indexing, and interpretable routing algorithms, it models how people chain together sequences of places for errands, work, and leisure.Sun, 05 Oct 2025 00:00:00 GMTPlaceAgentsAgent-Based ModellingOpenStreetMapH3 GridsPedestrian MovementUrban AnalyticsJ. Williamshttps://jwilliams.science/blog/placecrafter-urban-functional-regions/https://jwilliams.science/blog/placecrafter-urban-functional-regions/PlaceCrafter is a web-based platform that enables researchers to identify meaningful urban regions through clustering OpenStreetMap Points of Interest. Built with React, Leaflet, and D3.js, it provides interactive clustering, statistical validation, and platial visualisation of how cities are actually used.Fri, 03 Oct 2025 00:00:00 GMTPlaceCrafterOpenStreetMapUrban AnalyticsGISClustering & ClassificationOpen SourceJ. Williamshttps://jwilliams.science/blog/leisure-walking-systems/https://jwilliams.science/blog/leisure-walking-systems/A comprehensive reflection on a three-month Horizon CDT Impact Grant project that delivered industry-ready resources for leisure walking systems, exploring achievements, challenges, and broader implications for academic-industry collaboration.Tue, 16 Sep 2025 00:00:00 GMTWalking SystemsResearch ImpactPlace TheoryJ. Williamshttps://jwilliams.science/blog/diabetes-in-mexico/https://jwilliams.science/blog/diabetes-in-mexico/An overview of our W2GIS 2025 paper analysing diabetes-related hospitalisations and deaths in Mexico from 2005–2022, using the marginalization index to understand how social inequalities shape health outcomes.Sun, 14 Sep 2025 00:00:00 GMTHealth GeographySpatial ComputingUrban AnalyticsJ. Williamshttps://jwilliams.science/blog/os3-security-studio-launch/https://jwilliams.science/blog/os3-security-studio-launch/Explore OS³: an open teaching platform with modular labs covering SQLi, XSS, CSRF, SSRF, access control, cryptography, logging, monitoring, and network defence. Ideal for higher education, professional upskilling, and community workshops.Sun, 14 Sep 2025 00:00:00 GMTCybersecurityTeachingOpen SourcePythonJ. Williamshttps://jwilliams.science/blog/spatial-vs-platial/https://jwilliams.science/blog/spatial-vs-platial/An extended reflection on the difference between the spatial and the platial, why it matters for data, design, and everyday life, and how embracing both can transform how we map the world.Sat, 13 Sep 2025 00:00:00 GMTPlace TheorySpatial ComputingMapping & VisualizationJ. Williamshttps://jwilliams.science/blog/platial-atlas-mapping-lived-experience/https://jwilliams.science/blog/platial-atlas-mapping-lived-experience/Discover how the Platial Atlas project proposes capturing and representing places as they are lived and perceived by communities, using the PlaceCrafter framework to move beyond conventional geographic boundaries.Tue, 02 Sep 2025 00:00:00 GMTPlaceCrafterPlace TheoryGISMapping & VisualizationOpen SourceJ. Williamshttps://jwilliams.science/blog/h3-grid-introduction-demo/https://jwilliams.science/blog/h3-grid-introduction-demo/This hands-on tutorial introduces H3, Uber's open-source hexagonal grid system that's transforming spatial analysis. Learn why hexagons outperform traditional grids, set up H3 in JavaScript, and build interactive mapping applications with step-by-step code examples.Sat, 16 Aug 2025 00:00:00 GMTH3 GridsSpatial ComputingJavaScriptMapping & VisualizationTutorialsGISJ. Williamshttps://jwilliams.science/blog/placing-code-matters/https://jwilliams.science/blog/placing-code-matters/This manifesto-style post introduces the concept of 'placing code' - software development that respects geography, culture, and context. Drawing from research in Geographic Information Science and platial information systems, it argues for technology that serves human spatial relationships rather than replacing them.Sun, 03 Aug 2025 00:00:00 GMTPlace TheoryGISWeb DevelopmentJ. Williamshttps://jwilliams.science/blog/website-architecture-overview/https://jwilliams.science/blog/website-architecture-overview/This article will explore my experience of developing a new website for use as my main portfolio of work. My previous website had been developed and not updated for roughly three years and the new website will support enhanced project and blog-based updates. This article shares a few thoughts about my experiences in designing the new online presence.Sat, 12 Oct 2024 00:00:00 GMTWeb DevelopmentTutorialsJ. Williams