Thunderhead Explorer

This is a long overdue post following the clustering post where I wanted each flare element in a cluster symbol to flare to a different image symbol when the flare expands out. In addition, the default flare symbol expands upon a rollover mouse event, by me giving you the source code, you can customize it to expand on click, double click, shift click, whatever you want - you have the source code. The same applies to the flare elements. The ImageFlareSymbol has the same properties as the basic FlareSymbol but has two additional properties (backgroundWeights, backgroundColors) to color code the clusters based on their weight value. Each cluster is composed of one or more Graphic instance. In this implementation, each graphic must be symbolized with an instance of ImageFlareElementSymbol. The latter has a property ‘href’ that reference a bitmap url that will be displayed as a flare element. Here is a sample application to show the image flare in action. And like usual, here is the sou...

Was asked if the WeightedClusterer can cluster features not just by proximity but by proximity and attribute property value. The idea is that there should be at least one cluster per unique attribute property value. Let me explain further:  The above snapshot is a clustering of cities based on proximity and country - note that despite the proximity of Belgium and The Netherlands, two distinct clusters have been created one for BE and the other for NL - now for France - there is a cluster containing one feature over Paris, however due to the distance from Paris (at that scale) a cluster was created based on 3 cities in the south of France. Make sense ? In the implementation of the AttrClusterer class that extends the ESRIClusterer class, we override the clusterGraphics function. This function is invoked indirectly by the Flex framework during the update of the display list. In this function, we overlay a virtual grid on the map. This grid acts as a spatial index. Features that are ...

Initially, while working on Gulf Of Mexico Response Map , the legend and table-of-content were two separate windows. That took too much real-estate, and a TOC layer was hard to correlate with the legend swatch by name only. So I set upon merging the legend window and the table-of-content into one window. There is plenty of TOC code as a visual tree component, but it is the legend UI that causes us trouble as there is no REST endpoint to get the layer swatch information. Well with the advent of FeatureLayer somebody can argue that this could be done. But you still have to go back and forth for each layer and get the rendering information. BTW, this will be remedied in 10.1, as a new REST endpoint will be introduced to get _all_ rendering information of a map service. In the meantime, I had to do something. As you can imagine the project map services were very dynamic and the layer content was changing constantly, so having a static legend is out of the question. There were attempt...

A customer came up to me at the User Conference and asked me if I can apply the same overlay method that I used in my OverlaySymbol application to position a geographic referenced image on a web mercator tiled base map; since esri is migrating most of its published maps on arcgis.com to web mercator. After talking it over with my friend Kerry (who is the final authority when it comes to map projections), he recommended that this should be a pixel by pixel operation due to the exponential latitude elongation nature of web mercator. So basically the algorithm is; for each output mercator pixel, convert it back to geographic, find out in the geographic image source what is the pixel color at that geographic location and assign that color to the output mercator pixel. Straight forward, I mean the web mercator transform is well known. I just have to do it a million time, and... that is when I started panicking. A million time loop in AS3 - that will take forever (well actually half a se...

I am a HUGE fan of Augmented Reality , and one of my favorite applications on the iPhone is Layar . In this post, I will "walk you" through how to setup a simple ArcGIS Layar Point Of Interests (POI) layer and how to expose it through the iPhone application. In addition, I created a small Flex application that will enable you to add POIs to that feature class through a python geo-processor task. BTW - this is heavily geared to using ESRI desktop and server tools and I'm assuming that you are familiar with these tools. First, request a developer key from http://dev.layar.com/ . This might take a couple of hours to get to you. So, in the meantime, let's get started. Using ArcCatalog, create a new point feature class called 'Layar' in a geodatabase with the following fields: Title (text), Line2 (Text), Line3 (Text), Line4 (Text), Attribution (Text), Type (Integer), ImageUrl (Text:512). Import that layer into a map document using ArcMap. Save and publish the ...

Following this post, Glenn G. found an "issue" when panning the map. I revisited the project and indeed there was a bug. Thanks Glenn. I updated the project and here is the result. In this project, I downloaded from geonames all cities with population over 15000 and plotted them on the map. The clustering of the cities (over 21,000) generated a cool heat map. Check it out and tell me what you think. And like usual, you can download the source code from here .

Found this great article "15 Ways Oracle Can Make Java Better (and Improve Its Stance with Developers)" - here is my "in the weed" take: Keep JavaONE - with heavy focus on developers. Embrace OSGi down in the core VM. Kill JavaFx - Work closer with Adobe on Flex / BlazeDS / LCDS . Improve Dynamic Language Support - groovy / scala / JRuby / Jython /etc... Talk to Google about ME (seriously?) / Android Kill NetBeans - Eclipse may be King, but IntelliJ is God ! Introduce new language primitives XML / Function / JSON. Improve language - set/get bean, native String ( switch myString {case "foo": ...}) as for casting. LINQ for Java - LCDS can help here. Talk to the Spring folks - there-is-only-one-framework-zuul :-) No "Effing" store ! So....what do you think ?