Spatial | 易学教程

sql geography to dbgeography?

阅读更多关于 sql geography to dbgeography?

问题 Maybe I'm missing something. I have a sql server column of the "Geography" datatype. I want to use the DbGeography type in my c# code. Any way to cast or convert from sql's geography to dbgeography? 回答1: Sorry for the late response - but saw this whilst searching for something else. Simply do the following: SqlGeography theGeography; int srid = 4326; // or alternative DbGeography newGeography = DbGeography.FromText(theGeography.ToString(), srid); To reverse it: DbGeography theGeography;

SQL Server 2008 Spatial: find a point in polygon

阅读更多关于 SQL Server 2008 Spatial: find a point in polygon

问题 I am using SQL Server 2008 spatial data types. I have a table with all States (as polygons) as data type GEOMETRY. Now I want to check if a point's coordinates (latitudes, longitudes) as data type GEOGRAPHY, is inside that State or not. I could not find any example using the new spatial data types. Currently, I have a workaround which was implemented many years ago, but it has some drawbacks. I've both SQL Server 2008 and 2012. If the new version has some enhancements, I can start working in

Crop for SpatialPolygonsDataFrame

阅读更多关于 Crop for SpatialPolygonsDataFrame

问题 I have two SpatialPolygonsDataFrame files: dat1, dat2 extent(dat1) class : Extent xmin : -180 xmax : 180 ymin : -90 ymax : 90 extent(dat2) class : Extent xmin : -120.0014 xmax : -109.9997 ymin : 48.99944 ymax : 60 I want to crop the file dat1 using the extent of dat2. I don't know how to do it. I just handle raster files using "crop" function before. When I use this function for my current data, the following error occurs: > r1 <- crop(BiomassCarbon.shp,alberta.shp) Error in function (classes

Python: find contour lines from matplotlib.pyplot.contour()

阅读更多关于 Python: find contour lines from matplotlib.pyplot.contour()

问题 This question was migrated from Mathematica Stack Exchange because it can be answered on Stack Overflow. Migrated 6 years ago . I\'m trying to find (but not draw!) contour lines for some data: from pprint import pprint import matplotlib.pyplot z = [[0.350087, 0.0590954, 0.002165], [0.144522, 0.885409, 0.378515], [0.027956, 0.777996, 0.602663], [0.138367, 0.182499, 0.460879], [0.357434, 0.297271, 0.587715]] cn = matplotlib.pyplot.contour(z) I know cn contains the contour lines I want, but I

What's the best way to store co-ordinates (longitude/latitude, from Google Maps) in SQL Server?

阅读更多关于 What's the best way to store co-ordinates (longitude/latitude, from Google Maps) in SQL Server?

问题 I\'m designing a table in SQL Server 2008 that will store a list of users and a Google Maps co-ordinate (longitude & latitude). Will I need two fields, or can it be done with 1? What\'s the best (or most common) data-type to use for storing this kind of data? 回答1: Take a look at the new Spatial data-types that were introduced in SQL Server 2008. They are designed for this kind of task and make indexing and querying much easier and more efficient. More information: MS TechNet: SQL Server 2008

Bulk insert with text qualifier in SQL Server

阅读更多关于 Bulk insert with text qualifier in SQL Server

问题 I am trying to bulk insert few records in a table test from a CSV file , CREATE TABLE Level2_import (wkt varchar(max), area VARCHAR(40), ) BULK INSERT level2_import FROM \'D:\\test.csv\' WITH ( FIRSTROW = 2, FIELDTERMINATOR = \',\', ROWTERMINATOR = \'\\n\' ) The bulk insert code should rid of the first row and insert the data into the table . it gets rid of first row alright but gets confused in the delimiter section . The first column is wkt and the column value is double quoted and has

Different legends and fill colours for facetted ggplot?

阅读更多关于 Different legends and fill colours for facetted ggplot?

问题 Sorry for not included any example data for my problem. I couldn’t find a way to easily produce an example shape file. Hopefully, experienced users of ggplot can see what I’d like to do from the description below. I’ve got: A data.frame X with information about sample plots ( plotid , var1 , var2 , var3 , var4 , …) A polygon shapefile Y with spatial information for the sample plots Importation of the shapefile Y (with maptools ) and fortify ing as data.frame Z ( ggplot2 ) works fine. melt ing

Check if point is in spatial object which consists of multiple polygons/holes

阅读更多关于 Check if point is in spatial object which consists of multiple polygons/holes

问题 I have a SpatialPolygonsDataFrame with 11589 objects of class \"polygons\". 10699 of those objects consists of exactly 1 polygon, however the rest of those objects consists of multiple polygons (2 to 22). If an object of consists of multiple polygons, three scenarios are possible: Sometimes, those additional polygons describe a \"hole\" in the geographic ara describe by the first polygon in the object of class \"polygons\". Sometimes, those additional polygons describe additional geographic

OSM初识（三）OSM Data

阅读更多关于 OSM初识（三）OSM Data

一导出数据将XML格式的OSM数据转换成另一种格式。二提取数据剪切你选择区域内的数据，或者提取出特定区域特定的特征三数据格式 OSM文件仅属于OSM，不能用别的软件打开。其中后缀为bz2，pdf的文件是为了节省空间压缩过的OSM文件。一个简单的OSM文件如下图所示： shapefiles是一种用来存储矢量地图数据的格式，是由几个不同文件组成的。比如：一个包含建筑物数据的shapefile可能含有下述三个文件： buildings.shp buildings.shx buildings.dbf 一个shapefile文件只能有一种元素（点/线/形状）特征。不像OSM，里面的每一个目标都可以有无数个Tags,但是shapefile文件元素特征的属性必须符合定义的表格结构，如下图所示。OSM数据可以转化成shapefiles。 OSM数据一般存储在PostgreSQL 数据库或者SQLite数据库。 OSM数据一般存储在PostgreSQL 数据库或者SQLite数据库。下载最新版PostgreSQL：http://www.postgresql.org/download/。会安装三部分文件： • PostgreSQL server：核心部分，数据库软件 • pgAdmin4/3：管理数据库的图形界面 • StackBuilder：用来增加另外的应用