qgis

I have no problem using the DB Manager in QGIS 2.18, but if I try to add a layer based on a long running query (1 min+), QGIS becomes entirely unusable. It would appear that every map pan, every mouse click, etc., is triggering some kind of layer refresh. This seems silly for one, especially given that you can right click the layer and request a refresh. And more important, it makes the application unusable. What am I doing wrong here? Is it not possible to create the layer and only have it update when requested? Obviously I can create materialized views in postgres for all the spatial queries

I'm looking for a way to display one of my Mapbox map in QGis (baselayer edited on mapbox.com & data uploaded from tilemill). Did someone here already find a way ? Is there a feature or a plugin to do that ? Thanks for your future answers ! Adrien Yesterday, I found two solutions by myself : 1) the pretty official "TileLayer Plugin" QGis plugin You'll have to write a TSV file (Tab Separated Values) with, at least, the name, the credits and the URL of your Mapbox map. The URL should look like : http://a.tiles.mapbox.com/v3/mapboxId.mapId/{z}/{x}/{y}.png You just have to replace mapboxId and

I am new to using QGIS so this question might be real easy but I just can't find the answer anywhere online. I need to use the module geojson in QGIS but it is not yet "installed". I've used import geojson and it says No module named geojson So my question is, how do I install geojson in QGIS or specifically PyQGIS? I've already downloaded geojson from a website called geojson-1.0.9. Which folder should I copy geojson into so that PyQGIS can find the geojson python module. Thanks! I managed to figure it out myself on how to do this. I am using a Macbook Pro 13" mid-2012 running OS X Yosemite

创客经常要干的事情都是从无到有，都将经历一个从创意、草图到模型、实体，然后电子电路开发、软件设计、作品集成这样一个完整的过程，才能将最初的创意实现出来，这里收集的软件包括：1、二维设计，2、三维设计与数字建模，3、3D打印控制软件，4、GIS地图与空间数据处理，5、机器人操作系统，6、开源硬件平台与软件工具集。这些工具基本能够满足准专业级别的软硬件融合的智能产品开发的需要，而且是完全免费、开源的。 最近做的一些东西，用到很多工具，有时候虚拟机出问题需要重装，消耗大量的时间。以前还有一些版本不太兼容，就放到了多个虚拟机里，但使用起来还是不方便，就产生了一个想法，把各种常用的工具放到一个操作系统的版本之中，做一个专用的操作系统版本。使用UbuntuKylin15.04，马上开干。 涉及到的软件全部为开源软件，包括二维设计、三维设计、3D打印、GIS、机器人操作系统等等。安装过程如下（工程浩大，一步步验证，遇到问题会把攻略记录下来，供大家参考）： 1、二维设计 1.1、Inkscape，矢量绘图软件 这个主要做前期创意的记录和草图绘制。 ＃ sudo add-apt-repository ppa:inkscape.dev/stable sudo apt-get install inkscape 1.2、GIMP，影像处理软件 媲美PhotoShop的开源影像处理软件。需要拍一些照片

I want to partition a US state into 20 parts of approximately equal population. I can do this using, say, tracts, ZIP codes or another smaller geography. I'm looking for an algorithm to do the partitioning. It can be in any language or software (ArcGIS, QGIS, python, PostGIS, R, node). For grouping or clustering algorithms I've looked at like k-means, ArcGIS Grouping Analysis, etc. These do not seem to do what's needed, since they group based on the similarity of a variable don't partition into equal size based on a variable. My quick look at ESRI's districting tool suggests that this might be

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I'm looking for a way to display one of my Mapbox map in QGis (baselayer edited on mapbox.com & data uploaded from tilemill). Did someone here already find a way ? Is there a feature or a plugin to do that ? Thanks for your future answers ! Adrien 回答1: Yesterday, I found two solutions by myself : 1) the pretty official "TileLayer Plugin" QGis plugin You'll have to write a TSV file (Tab Separated Values) with, at least, the name, the credits and the URL of your Mapbox map. The URL should look like : http://a.tiles.mapbox.com/v3/mapboxId.mapId

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: Traceback (most recent call last): File "D:/Study/qgis3/QGIS/cmake/FindPyQt5.py", line 34, in <module> import PyQt5.pyqtconfig ModuleNotFoundError: No module named 'PyQt5.pyqtconfig' During handling of the above exception, another exception occurred: Traceback (most recent call last): File "D:/Study/qgis3/QGIS/cmake/FindPyQt5.py", line 37, in <module> import PyQt5.QtCore ImportError: DLL load failed: Found SIP version: 4.19 Traceback (most recent call last): File "D:/Study/qgis3/QGIS/cmake/FindQsci.py", line 45, in <module> from PyQt5.Qsci

又熬夜了... 这篇博客可能会将QGIS数据管理部分和ArcGIS数据管理进行对比学习。 1. 本地数据文件与数据库(矢量) 1.1 文件 QGIS用的是shp文件、kml文件、geojson文件较多，gml也可... ArcGIS不用说，几乎全都支持（请放弃使用远古的Coverage格式・・・） 当前最通用还是shp文件，不是因为它性能优秀，是因为历史缘故。 1.2 本地数据库 QGIS我目前使用了GeoPackage这个本地数据库，它有3个子文件组成：*.gpkg、*.gpkg-wal、*.gpkg-shm ArcGIS本地数据库有两种，mdb已经不推荐了，大多数时候还是gdb ps：ArcGIS内置的数据结构规定了ArcGIS的数据库只能是面向对象的。 1.3 关系数据库 为了提高性能，一般采用关系数据库。 QGIS我目前已经学会Postgresql的PostGIS插件，通常称为PostGIS数据库 此外，QGIS还支持SpatialLite、SQLite、MySQL、Oracle、DB2这些数据库MS ArcGIS在ArcSDE的支持下，几乎所有的第三方关系数据库都可以连接上去，但是不一定是最新版本 PostGIS提供了一款shp/dbf2postgis工具，支持dbf或者shp文件（必须英文名）导入导出PostGIS数据库 2. QGIS数据编辑 肯定会有数据编辑的时候

本人QGIS菜鸟一枚，最近使用QGIS导出SLD样式时，发现样式导出失败，打开SLD时发现提示<!--SymbolLayerV2 GradientFill not implemented yet-->，如下图所示： 后来经过倒腾，发现解决这个问题的方法，需要先在QGIS中保存符号，然后再导出样式即可避免上述问题，如下图所示： ------------------------------------------------------------------------------------------------- QQ群：871934478 -------------------------------------------------------------------------------------------------

When creating a new user on our Potgis enabled database I run into the strange issue that that new user cannot access the postgis extension while earlier created users can. With my user account I get the following output: mydb => SELECT postgis_version(); postgis_version --------------------------------------- 2.3 USE_GEOS=1 USE_PROJ=1 USE_STATS=1 (1 row) With the new user I get the following: mydb => SELECT postgis_version() mydb-> ; ERROR: function postgis_version() does not exist LINE 1: SELECT postgis_version() ^ HINT: No function matches the given name and argument types. You might need