31:[{"id":"ed1e66229618f35cea34f8d55f7f4e5e22cb733498bdfb7276a49428100f59331d6223f1279ecdf0996ec365fbb1499b317ed4052d9fd7a6d3a5c49f48846fdd","href":"https://static.observableusercontent.com/files/ed1e66229618f35cea34f8d55f7f4e5e22cb733498bdfb7276a49428100f59331d6223f1279ecdf0996ec365fbb1499b317ed4052d9fd7a6d3a5c49f48846fdd","name":"humain.png","type":"image/png","lastModified":1666013014160.616,"size":35048},{"id":"8ac8df1d0e3a6d10c537a33092d8e0859c37b151571e8939454daa1168efa09a825f0feee7efb7057f92fad50cfcccc91c6f95be79797d965910291ab41db003","href":"https://static.observableusercontent.com/files/8ac8df1d0e3a6d10c537a33092d8e0859c37b151571e8939454daa1168efa09a825f0feee7efb7057f92fad50cfcccc91c6f95be79797d965910291ab41db003","name":"selection@1.png","type":"image/png","lastModified":1666012238783.608,"size":22057},{"id":"7fc23960148d26af5aed6af8e37c219d87b88c1cecf2b8f59acaafeff69822349a45c7c74efd63557b49e8b4aff42b64089bedc3053bc7212b8309df616478db","href":"https://static.observableusercontent.com/files/7fc23960148d26af5aed6af8e37c219d87b88c1cecf2b8f59acaafeff69822349a45c7c74efd63557b49e8b4aff42b64089bedc3053bc7212b8309df616478db","name":"echelle.png","type":"image/png","lastModified":1666011542910.842,"size":1081002},{"id":"8845b000f4b771f9bd588033a2487efbc158580e031cffb67cd777ba0653383429ea47d3d6a686a4fd30517e38f918a86599eca5d6fd334dcfbb61be6fa8b187","href":"https://static.observableusercontent.com/files/8845b000f4b771f9bd588033a2487efbc158580e031cffb67cd777ba0653383429ea47d3d6a686a4fd30517e38f918a86599eca5d6fd334dcfbb61be6fa8b187","name":"echelle2.png","type":"image/png","lastModified":1666011542776.906,"size":404414},{"id":"554011f00786d916ad99aa78e856275e911d21480270a8948429f27fa384656e91a4a5f0e1e6aab95c4b21da796ec9eb7bfead124817b96178a58b6024231e02","href":"https://static.observableusercontent.com/files/554011f00786d916ad99aa78e856275e911d21480270a8948429f27fa384656e91a4a5f0e1e6aab95c4b21da796ec9eb7bfead124817b96178a58b6024231e02","name":"styles.png","type":"image/png","lastModified":1666011415357.999,"size":62369},{"id":"74e76e64b3f525343cc19dde5376f76c207a471eb7095d18169dd6b2f34cf3787ffdd4a304b8aedf0bbe81acf4bba1e6d6782e3eb9e753f04d7211c03bd8c238","href":"https://static.observableusercontent.com/files/74e76e64b3f525343cc19dde5376f76c207a471eb7095d18169dd6b2f34cf3787ffdd4a304b8aedf0bbe81acf4bba1e6d6782e3eb9e753f04d7211c03bd8c238","name":"structurale.png","type":"image/png","lastModified":1666011304891.02,"size":105321},{"id":"38f86d83bc071aa968c900a48afa29aa314f64808b8c66bc61fe4f201ca2b60583e1aa3da6cadeefee6a50a8c0eb4852d0437df384785bc7d1eb5da74cc4938e","href":"https://static.observableusercontent.com/files/38f86d83bc071aa968c900a48afa29aa314f64808b8c66bc61fe4f201ca2b60583e1aa3da6cadeefee6a50a8c0eb4852d0437df384785bc7d1eb5da74cc4938e","name":"conceptuelle.png","type":"image/png","lastModified":1666011122681.079,"size":51943},{"id":"a79a976a7e791686c608e015945d9911a4fafc7768426b42a24b87d66f22c6bd8df5f5738bcb9ce448e4c1e1ed6c3816eb7c5968c527f898330dc35db09a4679","href":"https://static.observableusercontent.com/files/a79a976a7e791686c608e015945d9911a4fafc7768426b42a24b87d66f22c6bd8df5f5738bcb9ce448e4c1e1ed6c3816eb7c5968c527f898330dc35db09a4679","name":"harmonisation.png","type":"image/png","lastModified":1664884233056.528,"size":67087}] 2f:{"title":"La généralisation","cells":[{"id":0,"value":"# La généralisation","pinned":false,"hidden":false,"mode":"md"},{"id":264,"value":"disclaimer","pinned":false,"hidden":false,"mode":"ojs"},{"id":41,"value":"viewof size = Inputs.range([400, 1000], {\n label: \"image width\",\n step: 10,\n value: 700\n})","pinned":false,"hidden":false,"mode":"ojs"},{"id":9,"value":"## 1. Enjeux, principes, questions","pinned":false,"hidden":false,"mode":"md"},{"id":11,"value":"Toute carte est une reproduction réduite d'une portion de l'espace géographique. Par construction, cela suppose une simplification des tracés. En effet, la réduction d'échelle combinée à l'épaisseur des traits oblige le cartographe a effectuer une simplification pour faciliter la lecture. \n\nLa généralisation cartographique résulte de quatre objectifs\n\n- Pragmatique : améliorer la lisibilité de la carte,\n- Scientifique : éliminer toute surcharge graphique,\n- Technique : alléger le fond de carte en diminuant le nombre de coordonnées stockées en mémoire,\n- Esthétique: dessiner selon un stylé donné.\n\nPlusieurs concepts sont inhérents au processus de généralisation : selection, schematisation (structurale et conceptuelle) et l'harmonisation.\n\n","pinned":false,"hidden":false,"mode":"md"},{"id":199,"value":"## 2. La sélection","pinned":false,"hidden":false,"mode":"md"},{"id":214,"value":"La selection consiste au choix des éléments des éléments à représenter. ICi, on élimine les îles (critère de surface).","pinned":false,"hidden":false,"mode":"md"},{"id":211,"value":"

","pinned":false,"hidden":false,"mode":"html"},{"id":13,"value":"## 3. Schématisation structurale","pinned":false,"hidden":false,"mode":"md"},{"id":189,"value":"La schématisation structurale consiste en une simplification des tracés. ","pinned":false,"hidden":false,"mode":"md"},{"id":187,"value":"

","pinned":false,"hidden":false,"mode":"html"},{"id":217,"value":"A la main, cette opération peut s'effectuer en définissant un crayon plus ou moins épais.","pinned":false,"hidden":false,"mode":"md"},{"id":153,"value":"

","pinned":false,"hidden":false,"mode":"html"},{"id":23,"value":"## 4. Schématisation conceptuelle ","pinned":false,"hidden":false,"mode":"md"},{"id":219,"value":"La schématisation conceptuelle est une simplification qui intègre des éléments d'interprétation (agrégations d'objets, changement de figuration, etc). On la retrouve beaucoup dans les cartes topographiques. ","pinned":false,"hidden":false,"mode":"md"},{"id":169,"value":"

","pinned":false,"hidden":false,"mode":"html"},{"id":29,"value":"## 5. Harmonisation","pinned":false,"hidden":false,"mode":"md"},{"id":225,"value":"L'harmonisation est une opération d’homogénéisation générale du fond carte entre tous les éléments qui le composent. ","pinned":false,"hidden":false,"mode":"md"},{"id":97,"value":"

","pinned":false,"hidden":false,"mode":"html"},{"id":174,"value":"## 6. La généralisation dépend de l'échelle","pinned":false,"hidden":false,"mode":"md"},{"id":229,"value":"La façon dont on va simplifier une fond de carte dépend de l'échelle de la carte (ou sa taille)","pinned":false,"hidden":false,"mode":"md"},{"id":184,"value":"

","pinned":false,"hidden":false,"mode":"html"},{"id":36,"value":"## 7. Des choix humains","pinned":false,"hidden":false,"mode":"md"},{"id":232,"value":"Derrière la généralisation des fonds de cartes, il y des choix humain. Qu’est ce qui est important, qu'est ce qui ne l'est pas au regard de la thématique traitée. Par exemple, une carte du monde sur la démographie se désintéressera des îles Caïman. Mais une carte du monde sur l'évasion fiscale sur-représentera ce territoire. ","pinned":false,"hidden":false,"mode":"md"},{"id":44,"value":"

","pinned":false,"hidden":false,"mode":"html"},{"id":31,"value":"## 8. Styles","pinned":false,"hidden":false,"mode":"md"},{"id":245,"value":"La généralisation cartographique, c'est aussi le moment où on va choisir un style graphique. Plutôt angulaire ? Plutôt sinueux ? Tout est possible. ","pinned":false,"hidden":false,"mode":"md"},{"id":104,"value":"

","pinned":false,"hidden":false,"mode":"html"},{"id":123,"value":"viewof k2 = Inputs.range([0.01, 0.1], {\n label: \"simplification\",\n step: 0.01,\n value: 0.03\n})","pinned":false,"hidden":false,"mode":"ojs"},{"id":114,"value":"sketch(world, {\n fill: \"none\",\n width: size,\n paper: false,\n k: k2,\n stroke: \"black\",\n strokeWidth1: 1,\n strokeWidth2: 0\n})","pinned":false,"hidden":false,"mode":"ojs"},{"id":33,"value":"## 9. En pratique","pinned":false,"hidden":false,"mode":"md"},{"id":92,"value":"En pratique, seule la shéatisation structurale est vraiment automatisable. Pour cela, on peut utiliser la librairie [geotoolbox](https://github.com/neocarto/geotoolbox)","pinned":false,"hidden":false,"mode":"md"},{"id":55,"value":"geo = require(\"geotoolbox@1.9.1\")","pinned":false,"hidden":false,"mode":"ojs"},{"id":75,"value":"viewof k = Inputs.range([0.01, 0.5], {\n label: \"Simplification\",\n step: 0.01,\n default: 0.25\n})","pinned":false,"hidden":false,"mode":"ojs"},{"id":80,"value":"world2 = geo.simplify(world, {\n k\n})","pinned":true,"hidden":false,"mode":"ojs"},{"id":63,"value":"bertin.draw({\n params: { width: size, projection: \"Robinson\" },\n layers: [\n { geojson: world2, fill: \"#316585\", stroke: \"white\" },\n { type: \"graticule\" },\n { type: \"outline\" }\n ]\n})","pinned":false,"hidden":false,"mode":"ojs"},{"id":144,"value":"## 10. Autres outils \"click bouton\"","pinned":false,"hidden":false,"mode":"md"},{"id":146,"value":"- Pour simplifier : https://mapshaper.org/\n- Pour visualiser et dessiner : http://geojson.io/","pinned":false,"hidden":false,"mode":"md"},{"id":49,"value":"## - Annexes -","pinned":false,"hidden":false,"mode":"md"},{"id":53,"value":"import { world } from \"@cartographie/quelques-donnees-sur-lafrique\"","pinned":false,"hidden":false,"mode":"ojs"},{"id":61,"value":"bertin = require(\"bertin@1.2\")","pinned":false,"hidden":false,"mode":"ojs"},{"id":111,"value":"import { sketch } from \"@neocartocnrs/cartographic-doodles\"","pinned":false,"hidden":false,"mode":"ojs"},{"id":281,"value":"import { disclaimer } from \"d41fbc44e11a58e6\"","pinned":true,"hidden":false,"mode":"ojs"}],"files":"$W31","stdlib":"1","titling":"auto"}