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artlembo
Sep 18, 20191 min read
Virtual 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...
222 views0 comments
artlembo
Mar 14, 20193 min read
Easy bivariate map with Postgres
A friend recently asked me about the cool looking bivariate maps produced with ArcOnline, lamenting that the capability seemed lacking...
234 views1 comment
artlembo
Oct 16, 20185 min read
Big Data Results
I 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...
150 views0 comments
artlembo
Jul 7, 20182 min read
Finding “Dangles” with PostGIS
Do 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...
587 views0 comments
artlembo
Jun 22, 20181 min read
Multi-Ring (non-overlapping) Buffers with PostGIS
I 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...
270 views0 comments
artlembo
Jun 19, 20181 min read
GIS Analysis of Overlapping Layers
Sure 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...
73 views0 comments
artlembo
Nov 21, 20171 min read
Big Data GeoAnalytics – Turning Points to Lines
In 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...
17 views0 comments
artlembo
Nov 20, 20171 min read
Big data geo-analytics with SQL
I’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...
24 views0 comments
artlembo
Mar 26, 20172 min read
Maryland 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...
6 views0 comments
artlembo
Dec 17, 20164 min read
Undergraduate Geospatial Python Projects
GIS Programming students presented their programming projects to ESRI. First, I cannot say enough to thank ESRI for taking time out of...
280 views0 comments
artlembo
Oct 25, 20162 min read
A Typical Class Project at Salisbury University: Evaluating Geocoding Accuracies
I’ve always been proud of our Salisbury University GIS students, and love to push them as far as their little minds can handle it. You...
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artlembo
May 18, 20163 min read
Open Source GIS Course at UMD – the Syllabus
UMD provided me with enrollment numbers, and we are getting a pretty full class. However, a few people on the “outside” have asked for a...
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artlembo
Apr 26, 20163 min read
k-Nearest Neighbor with PostGRES
Well, even though you didn’t ask for it, I decided to create a k-nearest neighbor analysis in PostGRES/PostGIS. This has lots of...
221 views0 comments
artlembo
Apr 26, 20162 min read
k-nearest neighbor with SQL in Radian Studio
I 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...
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artlembo
Apr 20, 20164 min read
Trade Area Analysis in Postgres / PostGIS
How 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...
25 views0 comments
artlembo
Apr 19, 20162 min read
SQL and ogr to create 4D lines
A friend recently asked me to help him generate polyline shapefiles with Z and M values that he could deliver to a customer. The problem...
21 views0 comments
artlembo
Jul 13, 20151 min read
Doing a GROUP BY in ArcGIS
As 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...
49 views0 comments
artlembo
Jun 5, 20152 min read
Radian Engine and Functions
In previous posts, I showed how to create ARC/INFO functions in SQL using Manifold 8. While I love SQL, it is somewhat frustrating to...
15 views0 comments
artlembo
Jun 8, 20142 min read
Spatial is Not Special – Quadrat Analysis
In our book we illustrated the use of quadrat analysis for determining whether points were random, clustered, or distributed. Figure...
34 views0 comments
artlembo
May 30, 20142 min read
Spatial is Not Special – Nearest Neighbor Index
It is nice to get back to the book, and start talking about Statistical Problem Solving in Geography again. Today we are going to look...
26 views0 comments
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