A friend recently asked me about the cool looking bivariate maps produced with ArcOnline, lamenting that the capability seemed lacking...

A friend is doing some research on estrogen and estrodial in water samples in Delaware. We have about 50 sub-watersheds that show the...

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...

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...

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...

GIS Programming students presented their programming projects to ESRI. First, I cannot say enough to thank ESRI for taking time out of...

CLICK TO VIEW Jeff Scarmazzi presenting on h0w to create editing rules and triggers using Postgres and PostGIS Today I want to introduce...

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...

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...

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...

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...

My good friend Stuart Hamilton gave me a fun conundrum to try out. He has a file of province boundaries (400 areas) and lidar derived...

I 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...

In addition to SQL, I also am interested in processing large volumes of spatial data.  One of the newest rages in “big data” is Hadoop....