artlemboSep 18, 20191 minVirtual layers with QGIS – wait a second, this is starting to look like Manifold…If you are like me, you love writing spatial SQL. But what can you do if you have a geodatabase, some shapefiles, or any other data format? Well, you can a...
artlemboMar 14, 20193 minEasy bivariate map with PostgresA friend recently asked me about the cool looking bivariate maps produced with ArcOnline, lamenting that the capability seemed lacking in ArcGIS. Well, it ...
artlemboOct 16, 20185 minBig Data ResultsI wanted to revisit the taxi data example that I previously blogged about. I had a 6GB file of 16 million taxi pickup locations and 260 taxi zones. I wante...
artlemboJul 7, 20182 minFinding “Dangles” with PostGISDo you have a set of lines that you need to determine if there are any “dangle” nodes? A dangle is a line segment that overhangs another line segment. Now,...
artlemboJun 22, 20181 minMulti-Ring (non-overlapping) Buffers with PostGISI was interested in creating mult-ring buffers but with a twist: I didn’t want the buffers to overlap one another. In other words, if I had concentric buffe...
artlemboJun 19, 20181 minGIS Analysis of Overlapping LayersSure you can solve it with a few for loops, inserting the results into a new table, but that really is a hassle. Also, I have to do it for different distan...
artlemboNov 30, 20171 minBig Data GeoAnalytics – adding dataContinuing my series on big data geoanalytics, I wanted to show how to bring in large data sets so that we can start working with them. The data set we’ll us...
artlemboNov 21, 20171 minBig Data GeoAnalytics – Turning Points to LinesIn my last video, I gave a short of mile-high view of how SQL can be used for big data geoanalytics. I want to dive a little deeper, and explore the idea of...
artlemboNov 20, 20171 minBig data geo-analytics with SQLI’m getting ready to create a course in big data analytics with GIS. I have lots of ideas as to what to do, but one thing I know is that I will be using spa...
artlemboMar 26, 20172 minMaryland State GIS Conference (TuGIS)The TuGIS training workshop on March 20, 2017 is completed – you can see the workshop evaluations below: The workshop evaluations are in (if you want to cut ...
artlemboMar 1, 20171 minRadian can read ESRI geodatabasesprevious video, I showed how Radian studio can read data directly from PostgreSQL, SQLite, and also easily exchange data between them. This is just another...
artlemboJan 27, 20172 minWorkshops at the Maryland Geospatial Conference#TUgis2017) is on March 20/21, 2017. I first attended TUgis in 1990, and it is always a great conference. It is not too large, so it is great way to have ...
artlemboDec 18, 20164 minUndergraduate Geospatial Python ProjectsGIS Programming students presented their programming projects to ESRI. First, I cannot say enough to thank ESRI for taking time out of their schedule to meet...
artlemboMay 26, 20162 minAdvanced Editing Capabilities with PostGISCLICK TO VIEW Jeff Scarmazzi presenting on h0w to create editing rules and triggers using Postgres and PostGIS Today I want to introduce you to another one o...
artlemboMay 18, 20163 minOpen Source GIS Course at UMD – the SyllabusUMD provided me with enrollment numbers, and we are getting a pretty full class. However, a few people on the “outside” have asked for a little more depth i...
artlemboApr 26, 20163 mink-Nearest Neighbor with PostGRESWell, even though you didn’t ask for it, I decided to create a k-nearest neighbor analysis in PostGRES/PostGIS. This has lots of potential: find the 5 neare...
artlemboApr 26, 20162 mink-nearest neighbor with SQL in Radian StudioI wanted to give you another look at some features that Radian Studio will offer. I’ve shown how we can use SQL to replicate the ARC/INFO NEAR function, and ...
artlemboApr 20, 20164 minTrade Area Analysis in Postgres / PostGISHow I used SQL to generate an accumulated sum of spatial data My friend Tomas does work with business analytics, and wanted to find a way to perform trade ar...
artlemboApr 19, 20162 minSQL and ogr to create 4D linesA friend recently asked me to help him generate polyline shapefiles with Z and M values that he could deliver to a customer. The problem was, the software h...
artlemboJul 13, 20151 minDoing a GROUP BY in ArcGISAs most of you know, I am a big fan of spatial SQL. It is my go-to tool whenever working with GIS. But, I have seen too many people using ArcGIS get trippe...