Want to keep yourself up to date with the latest news from Gisadvisor?
Subscribe using the "Follow" button below and we provide you with customized updates, via topic or tag, that get delivered to your email address, your smartphone or on your dedicated news page on follow.it.
You can unsubscribe at any time painlessly.
Title of Gisadvisor: "Gisadvisor | open source gis | esri technology"
Is this your feed? Claim it!
We'll continue our look into ESRI commands in PostGIS by examining another simple task: calculating the Mean Center of a data set. To illustrate these concepts, I will be showing examples from my book Statistical Problem Solving in Geography . In my textbook, I have an example of 7 data points: So, we can recreate the same results with the following SQL: this query gets the ave...
If you've worked with ARC/INFO (or any GIS really), you often have to make a determination about the coordinate system of your data: if you want to reproject the data into another coordinate system, you use PROJECT , but if you want to simply overwrite the coordinate system of a layer, you would use DEFINE PROJECTION . PostGIS allows you to do both commands rather easily. So tod...
Rather than starting with the easiest or hardest function, I thought I'd start somewhere in the middle - for GIS experts I don't want to bore you, and for novices, I don't want to blow you away with something more complex. But, after this post, we'll work through some easy queries and move on to more advanced queries. For those of you who used ARC/INFO, you probably found that t...
Two of my favorite things: my trusty ARC/INFO mug from 1990, and my trusty dog Pepper, painted in the style of Andrew Wyeth's Homer . At the recent FOSS4gNA conference , I had the pleasure of hearing about some of the new features in PostGIS. One such set of features were the Coverage related features ( ST_CoverageInvalidEdges , ST_CoverageUnion , ST_CoverageSimplif y ). These f...
