c# – geoMusings

ToGeoJson and ToWKT for the Esri FGDB API

2012-08-24 by Bill Dollins

In support of some of our ongoing PIM work, we’ve been integrating the Esri File Geodatabase (FGDB) API into some tools. Without going into a level of detail that would hijack this post, one of the many functions performed by some of the tools is to validate physical spatial databases against established data models to analyze compliance and identify differences. These databases may be in Esri or non-Esri formats and we have traditionally handled Esri geodatabases through ArcObjects since it provides a relatively uniform interface across the various flavors of geodatabase.

Of course, ArcObjects requires an ArcGIS license of some sort and we are finding out that this is not always available to users in the field under many situations so the FGDB API gets past that for file geodatabases, at least.

Using GeoIQ Analytics in .Net Applications

2012-07-18 by Bill Dollins

A few weeks ago, I posted about some .Net wrappers I created for the GeoIQ API. Due to ongoing project work, I have continued to extend them by adding methods to wrap GeoIQ analytical capabilities. Despite the recent acquistion of GeoIQ by Esri, it’s my understanding that GeoCommons and existing GeoIQ installations will continue for some time. That’s good, because analytics on the GeoIQ platform are powerful and fairly easy to use. This post will demonstrate how to use analytics in a .Net application.

As previously posted, the .Net wrappers can be found on github here.

The GeoIQ platform offers several functions to analyze data sets hosted on a GeoIQ instance or GeoCommons. I have not yet wrapped all of the functions but am working my way through them as I can.

For this post, I will intersect the locations of US GISPs as of 1/26/2011 with the Maryland Zip Code Boundaries to produce a data set containing the locations of GISPs in Maryland, depicted in the map below.

intersect_results — Don’t worry, none of these are me.

GeoIQ API Wrappers for .Net

2012-06-11 by Bill Dollins

A while back, I built a small interface between GeoIQ/GeoCommons and ArcGIS Desktop. From there, it became more of a full-fledged toolbar for ArcGIS. During that effort, I began developing some .Net classes to wrap the GeoIQ RESTful API. As we progressed with the toolbar, my colleague Hugo Estrada also contributed to the library.

The original intent was to wrap the entire API but it turns out that we were undertaking this in the middle of GeoIQ’s upgrade to version 2.0. In the intervening time, we got some projects implementing the GeoIQ platform for end users (such as the Climascope portal that Andrew Turner recently blogged about).

Working with the GeoIQ Features API

2011-04-07 by Bill Dollins

I find myself pointing people to GeoCommons for data more often these days. With over 50,000 data sets, there’s a lot there. The people I work with seem to usually be able to find data of value there so I’ve been putting a little time into making it easier to get data from GeoCommons. As I’ve mentioned before, many of them are long-standing ESRI users. While they are becoming more aware of alternate tools and data sources, it is still important for them to be able to get data into the ESRI environment where their custom tools reside.

Given the content of my recent posts, it’s no secret that my recent project work has involved the ESRI Silverlight API so I decided extend it to more easily access data from GeoCommons.

Recently, GeoIQ pubished an update to their RESTful API that includes a “Features API,” which gives you a little more direct access to the features in a GeoIQ data set (GeoIQ is the platform upon which GeoCommons is built). Previously, if I needed to access data from GeoCommons in the ESRI Silverlight API, I would just access it as KML using the native KmlLayer class. The GeoIQ Features API, however, offers more fine-grained control over how much data we return in the form of various query parameters. Currently, the API only returns JSON (GeoIQ’s own syntax or GeoJSON) so it was time to do something different.

Simple Annotations With the Esri Silverlight API

2010-12-16 by Bill Dollins

In a previous post, I mentioned that I developed a MeasureString function for use in developing an annotation tool. In this post, I’ll go into a little bit more detail about that tool. For purposes of discussion, I extended the interactive graphics sample from the Esri Silverlight API interactive SDK.

For starters, I added another tool to the sample’s tool bar (circled in red below) to provide access to the annotation capability.

DynamicLayer Auto-Refresh for ESRI Silverlight API

2010-11-01 by Bill Dollins

Despite recent news regarding Silverlight, I expect some of my projects to continue using it for the near term. Others may be taking the same tack, so I thought I’d go ahead and offer this up.

Several of the projects I support have the requirement to periodically refresh specific layers in order to track change or movement. These layers can range from weather to vehicle locations and such. I have typically accomplished this with a timer that refreshes the layer(s) on a specified interval. This can get rather cumbersome if you have different layers that require different refresh intervals.

Working within Silverlight, I have the option of using an existing layer class as a base class and extending it to include an automatic refresh capability. However, some classes, such as the ArcGISDynamicMapServiceLayer, are sealed and cannot be extended. Luckily, the Expression Blend SDK enables me to get around this by attaching a custom behavior.

MeasureString for Silverlight

2010-10-08 by Bill Dollins

I was working on an annotation tool for an application I am developing using the Esri Silverlight API. The TextSymbol class has properties to specify the X and Y offsets in order to position the text relative to the symbol’s base point. I needed to calculate the size of the string in order to determine the offset I wanted to use. Silverlight seems to have no intrinsic equivalent to the MeasureString function so I hacked this up.

zigGIS Hotfix Available

2010-06-18 by Bill Dollins

A Couple of Updates

2010-06-15 by Bill Dollins

Importing Data From GeoCommons Into ArcMap

2010-06-02 by Bill Dollins

UPDATE: The code for this post is available at the bottom of the page.

I have been doing a lot of development with the ESRI Silverlight API recently. One of the requirements of my project is to be able to dynamically add KML data at runtime. The incorporation of KML was handled for us through one of the ESRI samples on the resource center so we pretty much just had to integrate that code and test against our use cases. For testing, I typically reached out to GeoCommons since any data set available there can be streamed as KML.

Obviously, this is not my first exposure to GeoCommons but, when discussing it, I found that many of the analysts I spoke with were not aware of it and did not use it much. So I decided to tackle developing a simple ArcMap extension to allow a user to search GeoCommons and then download/add data to ArcMap without the need to manually download, unzip and add the data themselves.