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...
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...
artlemboDec 21, 20171 minWork smarter – not largerWhen you were in Statistics 101, and the Professor said ok, we are now going to learn about the Central Limit Theorem, did you tune out? Did you sarcasticall...
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...
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 ...
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...
artlemboJul 7, 20152 minWhen More is Less…. lessons from processing large data filesMy good friend Stuart Hamilton gave me a fun conundrum to try out. He has a file of province boundaries (400 areas) and lidar derived mangrove locations (37 ...
artlemboJun 26, 20151 minNew Books – How do I do that in PostGIS, How do I do that in Manifold SQLI have two new books out – How do I do that in PostGIS, and How do I do that in Manifold SQL. From the back cover of How do I do that in PostGIS: For those w...
artlemboJun 3, 20152 minAnother Radian Test – Finding the distance between lines and areasFollowing up on my previous post with ArcGIS and the Near Table, I created an SQL query in Manifold 8 to do both the near distances and group them by the num...
artlemboMay 22, 20150 minTesting Manifold Systems, Ltd. Experimental Parallel Processing Engine (Radian) – along with s
artlemboJun 9, 20142 minSpatial is Not Special – Quadrat AnalysisIn our book we illustrated the use of quadrat analysis for determining whether points were random, clustered, or distributed. Figure 14.9 from the book show...
artlemboMay 30, 20142 minSpatial is Not Special – Nearest Neighbor IndexIt is nice to get back to the book, and start talking about Statistical Problem Solving in Geography again. Today we are going to look at the Nearest Neighb...
artlemboMay 26, 20141 minARC/INFO Functions – Symmetrical DifferenceI was recently asked by danb to illustrate the ARC/INFO function symmetrical difference. We basically want to find those areas in layer A that don’t intersec...
artlemboMay 23, 20142 minARC/INFO Functions – UNIONWe are going to conclude our overlay posts with the ARC/INFO UNION command. This should be a lot easier than it actually is. I think the problem is that Ma...
artlemboMay 21, 20142 minARC/INFO Functions in SQL – IDENTITYThe ARC/INFO IDENTITY operation seen here is sometimes confusing because it takes ALL of the Input feature, and the part of the IDENTITY feature that interse...
artlemboMay 2, 20142 minSpatial is Not Special – Modifiable Area Unit Problem (MAUP)I wrote a paper in 2006 about using SQL for the Modifiable Area Unit Problem (MAUP). The example was an agricultural experiment field, and I showed how SQL ...
artlemboApr 23, 20142 minThe ARC/INFO NEAR Function in SQLLets take another break from my textbook, and focus on a classic GIS operation. If you are like me, you learned GIS with ARC/INFO. I started with ARC/INFO ...
artlemboApr 22, 20142 minStream Sinuosity with Spatial SQLIn case you are getting tired of reading examples from my book (did I mention that I have a textbook you can buy from Amazon?), I thought I would throw a pos...
artlemboApr 21, 20143 minSpatial is not special – Weighted Standard DistanceThis post is part of a series entitled Spatial is not Special, where I will illustrate how spatial constructs in SQL provide us with a rich toolset for geogr...
artlemboApr 18, 20142 minSpatial is Not Special – Standard DistanceThis post is part of a series entitled Spatial is not Special, where I will illustrate how spatial constructs in SQL provide us with a rich toolset for geogr...