[{"data":1,"prerenderedAt":292},["ShallowReactive",2],{"project-43971314":3},{"id":4,"name":5,"line":6,"line_source":7,"title":8,"url":9,"domain":10,"maker":11,"posted_at":12,"year":13,"points":14,"comments":15,"rank_in_year":16,"shown_in_year":17,"top":18,"tier":19,"category":20,"subcategory":21,"format":22,"keywords":23,"reception":29,"sentiment":30,"stance_mix":31,"scored_comments":35,"aspects":36,"strip":42,"post_text":45,"what":46,"said":83,"maker_in_thread":172,"shape":183,"grid":187,"attempts":254,"same_week":255,"maker_shows":235,"maker_hidden":284,"reader_version":285,"card":286},"43971314","A5","Yes, those are the obvious ones.","maker","Show HN: A5","https:\u002F\u002Fgithub.com\u002Ffelixpalmer\u002Fa5","github.com","pheelicks",1747130566,2025,95,29,766,3837,20,"notable","languages","geospatial indexing library","library",[24,25,26,27,28],"geospatial index","equal area","discrete global grid","h3","s2","curious",-0.086,{"positive":32,"neutral":33,"mixed":34,"critical":32},2,9,0,13,{"docs":37,"design":38,"idea":40,"performance":41},{"positive":34,"critical":34},{"positive":39,"critical":39},1,{"positive":34,"critical":39},{"positive":34,"critical":34},[43,34,34,43,34,43,34,44,44,43,34,34,34,43,34,34,43,34,39,34,43,34,39,34,43,34,43,34,34],3,5,null,{"problem":47,"audience":57,"pricing":45,"motivation":68,"time_to_build":45,"stack":72,"openness":81,"stage":82,"team_size":81},{"value":48,"source":7,"evidence":49},"Spatial indexing where cells have equal area, unlike H3 which varies by up to about 2x",[50,53],{"id":51,"by":11,"text":52},"43972653","Yes, those are the obvious ones. This example: https:\u002F\u002Fa5geo.org\u002Fexamples\u002Fairbnb shows why the equal area is valuable in practice, while https:\u002F\u002Fa5geo.org\u002Fexamples\u002Farea shows the…",{"id":54,"by":55,"text":56},"43972566","carderne","Can you give some examples of when this might be better to use than H3? The ones that seem obvious: - You need very high resolution. H3 is also 64 bit I think, but it seems like…",{"value":58,"source":59,"evidence":60},"Developers doing spatial joins, aggregation and density analysis on geographic data","inferred",[61,62,65],{"id":51,"by":11,"text":52},{"id":63,"by":11,"text":64},"43975112","If you're aggregating and comparing data across different locations for example: https:\u002F\u002Fa5geo.org\u002Fexamples\u002Fairbnb",{"id":66,"by":11,"text":67},"43973832","As a user, you generally don’t care about the math (and S2 is hardly simple either, as it warps the squares prior to projection). You just call the API and use the indices for…",{"value":69,"source":7,"evidence":70},"Offer an alternative to S2 and H3 with different strengths and weaknesses",[71],{"id":51,"by":11,"text":52},[73],{"value":74,"source":75,"evidence":76},"TypeScript reference implementation","commenter",[77],{"id":78,"by":79,"text":80},"43974092","zX41ZdbW","H3 and S2 are supported out of the box in ClickHouse and have reference libraries in C and C++. But it looks like A5 only has a reference implementation in TypeScript. Porting…","unknown","beta",{"praise":84,"objections":95,"requests":118,"questions":130,"alternatives":149},[85,89],{"value":86,"source":7,"evidence":87},"Equal-area cells are valuable in practice",[88],{"id":51,"by":11,"text":52},{"value":90,"source":75,"evidence":91},"Interesting aesthetics and approach",[92],{"id":93,"by":55,"text":94},"43978238","Haha that colour scale on the area variance page makes it a bit hard to see whether nearby H3 hexagons are very different in size...? I've never really investigated, but my…",[96,100,107,111],{"value":97,"source":75,"evidence":98},"Irregular shapes and non-uniform centroid distances are downsides",[99],{"id":54,"by":55,"text":56},{"value":101,"source":75,"evidence":102},"Dodecahedron optimisation seems an uncommon need",[103],{"id":104,"by":105,"text":106},"43974999","ralusek","> The benefit of choosing a dodecahedron is that it is the platonic solid with the lowest vertex curvature, and by this measure it is the most spherical of all the platonic…",{"value":108,"source":75,"evidence":109},"Only a TypeScript implementation so far",[110],{"id":78,"by":79,"text":80},{"value":112,"source":75,"evidence":113},"Title lacks a description",[114],{"id":115,"by":116,"text":117},"43974396","knowitnone","Please please please include a description in your title. Just a couple of words will do.",[119,123],{"value":120,"source":75,"evidence":121},"Ports to other languages such as C and C++",[122],{"id":78,"by":79,"text":80},{"value":124,"source":75,"evidence":125},"Show next-higher and next-smaller overlay like H3 landing page",[126],{"id":127,"by":128,"text":129},"43989980","i3oi3","The description of the algorithm notes that each irregular pentagon is divided into four sub-pentagons. Eyeballing the maps, I don't see any group of 4 pentagons forming a…",[131,138,142],{"value":132,"source":75,"evidence":133},"Advantage over HEALPix",[134],{"id":135,"by":136,"text":137},"43974102","xioxox","What's the advantage of this over HEALPix projection? https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FHEALPix",{"value":139,"source":75,"evidence":140},"Why use it instead of H3",[141],{"id":54,"by":55,"text":56},{"value":143,"source":75,"evidence":144},"Is it useful beyond visualization, e.g. database performance",[145],{"id":146,"by":147,"text":148},"43976858","Bedon292","Is it primarily useful just for data visualization? Would there be an potential performance benefits for something like searching a database for nearby data?",[150,158,168],{"value":151,"source":75,"evidence":152},"H3",[153,157],{"id":154,"by":155,"text":156},"43972870","jll29","A5 uses pentagons, Uber's H3 uses hexagons: H3: Uber’s Hexagonal Hierarchical Spatial Index https:\u002F\u002Fwww.uber.com\u002Fen-DE\u002Fblog\u002Fh3\u002F",{"id":54,"by":55,"text":56},{"value":159,"source":75,"evidence":160},"S2",[161,164],{"id":162,"by":11,"text":163},"43972901","Also check S2: http:\u002F\u002Fs2geometry.io\u002F, created at Google before H3, which uses squares and underpins the fast indexing in BigQuery amongst many other things",{"id":165,"by":166,"text":167},"43973641","yencabulator","So if I've understood correctly: Google's S2 is all about performance and prefix-matching. Uber's H3 makes the math a bit more complex to prioritize less variation in…",{"value":169,"source":75,"evidence":170},"HEALPix",[171],{"id":135,"by":136,"text":137},{"comments":173,"answered":174,"key":175},10,4,[176,177,180],{"id":51,"text":52},{"id":178,"text":179},"43975085","The base platonic solid that Healpix is based on is the octahedron (https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FOctahedron), which A5 uses the…",{"id":181,"text":182},"43981304","My mistake, you are correct. The base solid is indeed the rhombic dodecahedron. I believe the point about the angular defect is still valid though.",{"commenters":184,"max_depth":174,"maker_replies":173,"first_comment_mins":185,"lifespan_hours":186},18,189,46,[188,190,194,197,201,205,207,208,212,214,215,216,220,221,224,226,229,230,231,233,236,239,240,243,244,245,248,250,252],[115,34,43,189,116,34],"project\u002Fneutral\u002Fdocs",[191,34,34,192,193,34],"43976106","other\u002Fneutral\u002Fnone","divan",[195,34,34,192,196,34],"43976293","panzagl",[198,34,43,199,200,34],"43976738","project\u002Fneutral\u002Fdesign","riku_iki",[202,34,34,203,204,34],"43992723","commenter\u002Fneutral\u002Fdocs","badmonster",[54,39,43,206,55,34],"project\u002Fneutral\u002Fidea",[51,39,34,206,11,39],[209,39,44,210,211,34],"43974911","maker\u002Fpositive\u002Fnone","spencerflem",[93,39,44,213,55,34],"project\u002Fpositive\u002Fdesign",[135,32,43,206,136,34],[178,32,34,206,11,39],[217,32,34,218,219,34],"43977056","commenter\u002Fneutral\u002Fnone","pama",[181,32,34,218,11,39],[222,32,43,199,223,34],"43975193","michelpp",[225,32,34,199,11,39],"43975624",[227,43,34,192,228,34],"43973501","Tabular-Iceberg",[165,174,43,206,166,34],[66,174,34,206,11,39],[127,44,39,232,128,34],"project\u002Fcritical\u002Fdesign",[234,235,34,189,11,39],"43974045",6,[154,237,43,238,155,34],7,"project\u002Fneutral\u002Fnone",[162,237,34,238,11,39],[104,241,39,242,105,34],8,"project\u002Fcritical\u002Fidea",[63,241,34,206,11,39],[78,33,43,238,79,34],[246,33,34,247,11,39],"43974418","project\u002Fneutral\u002Fexecution",[146,173,43,249,147,34],"project\u002Fneutral\u002Fperformance",[251,173,34,249,11,39],"43977468",[253,173,34,192,147,34],"43978053",[],[256,261,266,271,276,280],{"id":257,"name":258,"points":259,"category":260},"43935394","Hyvector",331,"dev_tools",{"id":262,"name":263,"points":264,"category":265},"43928118","qtap",259,"infrastructure",{"id":267,"name":268,"points":269,"category":270},"43975423","HelixDB",237,"data",{"id":272,"name":273,"points":274,"category":275},"43988381","Muscle-Mem",226,"ai",{"id":277,"name":278,"points":279,"category":20},"43936097","Aberdeen",224,{"id":281,"name":282,"points":283,"category":275},"43964201","Airweave",176,false,"v2",{"id":287,"name":5,"line":6,"ai":284,"cat":20,"year":13,"points":14,"comments":15,"rec":29,"s":288,"top":18,"kw":289,"maker":11,"domain":10,"tier":19,"attempts":34,"strip":290,"url":9,"mix":291,"praise":86,"objection":97,"sub":21},43971314,-0.09,[24,25,26,27,28],"30030305530003003010301030300",[32,33,34,32],1794036674693]