geojson

OpenLayers create Layers from GeoJSON by property

由 做~自己de王妃 提交于 2020-03-05 07:54:32
问题 I want to use OpenLayers v5.3.0 to create a Web application. I’m able to show all features from a external GeoJSON File as a Vector Layer above a OSM Layer, but my GeoJSON File holds thousands of features, each enriched by a lot of properties. What I’m looking at is a way to be able to parse the GeoJSON File, filter it by properties (e.g. all features with the property "gender": "f", or "ethnic_gro": "Latvian", ) and display only those as an additional Vector Layer above my OSM Base Layer.

使用 plotly 绘制 Choropleth 地图

由 微笑、不失礼 提交于 2020-02-28 01:39:58
本文将通过绘制中国省级 Choropleth 地图来解释如何使用 plotly 绘制 Choropleth 地图，主要有两种方法：底层 API plotly.graph_objects.Choroplethmapbox 和高层 API plotly.express.choropleth_mapbox ，数据是 COVID-19 在某一天的疫情数据。 什么是 Choropleth 地图 Choropleth map 即分级统计图。在整个制图区域的若干个小的区划单元内（行政区划或者其他区划单位），根据各分区资料的数量（相对）指标进行分级，并用相应色级或不同疏密的晕线，反映各区现象的集中程度或发展水平的分布差别。—— Choropleth_百度百科 简单来说，具体到本文，就是在地图上为每个省上色，根据什么来确定上哪个颜色呢？在本文中就是该省的确诊人数，人数越多，颜色越亮。这样得到的地图就是 Choropleth 地图。 依赖 主要依赖为： plotly pandas 均可以通过 pip 安装，然后导入： import json import pandas as pd import plotly . express as px import plotly . graph_objs as go 数据准备 data.csv ：某日 COVID-19 全国省级疫情数据，用于地图上色 china

Loading JSON into a GeoDataFrame

由 …衆ロ難τιáo~ 提交于 2020-02-26 12:11:36
问题 I'm having difficulty loading the following JSON containing GIS data (https://data.cityofnewyork.us/resource/5rqd-h5ci.json) into a GeoDataFrame. The following code fails when I try to set the geometry. import requests import geopandas as gpd data = requests.get("https://data.cityofnewyork.us/resource/5rqd-h5ci.json") gdf = gpd.GeoDataFrame(data.json()) gdf = gdf.set_geometry('the_geom') gdf.head() 回答1: Setting the geometry fails because the geopandas.GeoDataFrame constructor doesn't appear

The geojson point data markers are not clustering in leaflet map

由 给你一囗甜甜゛ 提交于 2020-02-25 05:18:04
问题 I am using leaflet-markercluster plugin for cluster my point data. I already loaded my geojson data named as 'street' into map. this data having around 40 points with their respective attributes. I want to cluster these points in leaflet map. But even markers are not showing in my map. Please help me to find out the error. My code is here: var OpenStreetMap_Mapnik = L.tileLayer('https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', { maxZoom: 19, attribution: '© <a href="https://www

turf.nearestPoint only returning the same point

由 最后都变了- 提交于 2020-02-22 07:26:29
问题 I am making a Leaflet map. I am loading some geoJSON data. I have an on click function for the map. When I click I simply want to alert the nearest point from the loaded geoJSON. The problem is that only one point is returned no matter where I click in the city ( the point shown in the image below. //Create the map var map = L.map('mapdiv').setView([-43.534384, 172.640528], 13); // Add the basemap L.tileLayer('https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', { attribution: '© <a href=

turf.nearestPoint only returning the same point

由 跟風遠走 提交于 2020-02-22 07:26:22
问题 I am making a Leaflet map. I am loading some geoJSON data. I have an on click function for the map. When I click I simply want to alert the nearest point from the loaded geoJSON. The problem is that only one point is returned no matter where I click in the city ( the point shown in the image below. //Create the map var map = L.map('mapdiv').setView([-43.534384, 172.640528], 13); // Add the basemap L.tileLayer('https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', { attribution: '© <a href=

GeoJson用于表示地理信息数据

由 馋奶兔 提交于 2020-02-14 16:29:11
这几天一直在讨论关于一体化态势图的架构。首先大家明确了基于层次化架构，采用大量功能图层来表示承载不同类型的数据。我要解决的大量的地理信息数据的建模。目前底层的地理信息数据库的处理系统arcGIS等，可以高效管理地理信息数据库中的数据，提供层次化视图，也可以帮助用户轻松筛选所需要的数据，并提供相应的关联分析能力。 刚开始，我准备借鉴arcGIS的思想，将地理信息数据分层显示，每个图层都是功能单一的，例如，河流构成一个河流层，附带对河流操作的函数，路网分成公路网和铁路网，分别形成一个图层。再借鉴costmap_2d的思想，通过三层到master map的投影，构成一个虚拟的图层，对导航提供代价地图。如果将铁路网和公路网到虚拟的路网层做投影，则也可以当成一个路网层，对外提供先关数据。最底层是一个栅格化的空白图层，就是按照实际需要，将态势展示的区域进行栅格化，栅格化带来的好处是减小数据存储和处理的开销(一定面积的区域可以用该栅格的坐标表示）。 这需要说明的是，我在设计地理信息层的时候，是把它当做一个图层的集合来设计的，其下面包含很多子图层集合和基础功能图层。子图层集合也允许嵌套，直到最底层的图层集合只包含基础功能图层为止。对于某一个子图层，我们可以把它当做一个虚拟图层，是由其所有子图层集合和基础功能图层的投影。例如上面的路网层，就是背景轮廓层+公路网+铁路网进行的投影。另外

Restrict the viewable part of a tile to a polygon area in Leaflet?

由 冷暖自知 提交于 2020-02-05 03:49:14
问题 In Leaflet, how does one restrict the viewable part of a tile to the area contained within a polygon (or geojson), i.e., the intersection between a polygon and the tile beneath. Example use : display only one country and hide all others. EDIT: I'm not looking for the fitBounds/setMaxBounds method but for a way to display only the inner area of a polygon. 回答1: You can use the map.setMaxBounds(L.latLngBounds) method to restrict the view. For restricting the map view: map.fitBounds(polygon

Jackson deserialize GeoJson Point in Spring Boot

由 Deadly 提交于 2020-02-03 05:14:06
问题 I have a @Entity model that has a property of type com.vividsolutions.jts.geom.Point . When I try to render this model in a @RestController I get a recursion exception. (StackOverflowError); nested exception is com.fasterxml.jackson.databind.JsonMappingException: Infinite recursion (StackOverflowError) (through reference chain: com.vividsolutions.jts.geom.Point[\"envelope\"]- >com.vividsolutions.jts.geom.Point[\"envelope\"].... The entity looks like this (shortened for brevity): @Entity @Data

GeoJson features coordinates are in meters not in [lng, lat]. How to display in google map?

由 冷暖自知 提交于 2020-01-29 05:23:27
问题 Eg: [360590, 555610] - [lng, lat] in meters from google map api - GeoJson data { "type": "FeatureCollection", "features": [ { "type": "Feature", "geometry": { "type": "MultiPolygon", "coordinates": [ [ [ [ 360590, 555610 ], [ 360590, 555555.0128 ], [ 360590, 555540 ], [ 360592.4439, 555540 ], [ 360600, 555540 ], [ 360600, 555518.8277 ] ] ] ] } } ] } here, [360590, 555610] - [X, Y] coordinates is in meters, Now we need to display this coordinates on google map, Is there any solution for this?
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