Monthly Archives: August 2007
In this blog, we’ve presented several advanced techniques for map caching. If this blog were a book, we’d put the advanced information at the end, but we realize some of you may just be getting started with ArcGIS Server. If so, here’s your chance to learn what map caching is all about.
Map caching is a very effective way to make your ArcGIS Server maps run faster. When you create a map cache, the server draws the entire map at several different scales, then stores copies of the map images. The server can then distribute these images whenever someone asks for a map. It’s much quicker for ArcGIS Server to hand out a cached image than to draw the map each time someone requests it. Another benefit of caching is that the amount of detail in the image doesn’t noticeably affect how quickly the server can distribute the copy. Continue reading
Labor Day Weekend is approaching, there’s a heat wave in southern California, and clouds and even some raindrops seem to be all around. A likely escape for a long weekend getaway is one of the nearby National Parks, perhaps Yosemite. But what about the weather?
Here’s a quick little mashup of a couple of different services, showing real-time weather published by the Pennsylvania State University through the Pennsylvania Spatial Data Access site, along with live Web cam feeds from Yosemite National Park.
The weather is an ArcIMS service, and when we opened it in Explorer we set the service to update every 15 minutes, so we’d be seeing the latest weather conditions at regular intervals since late summer storms move quickly through the Sierra.
The Yosemite Web cams are published at the Yosemite Association Web site. We created several notes (using the Create Notes task) and entered the URL to the Web cams in the note text box.
Unfortunately the Web site didn’t publish the exact coordinates for the cams, but it did describe their locations. We added the Physical Features layer from the new Resource Center to our map, since it includes the 1:24000 scale topo maps for the US. We used the cam placement descriptions and the topo maps to locate each Web cam push pin. The cams are not at their exact physical locations, but close enough for our needs.
Finally, to organize things, we used the new Add Folder capabilities for results to group all of them under one “Yosemite Online” note. We also added links to the note that point to the National Park Service and Yosemite Association Web sites.
We’ve exported the note, and emailed it around to everyone on the team so they could open and see the same live cams and weather information in Explorer.
By Charlie Frye, Esri Chief Cartographer
When an elevation raster dataset contains values for both topography and bathymetry, often the best solution to this is to split it into two new rasters: one for the topography and one for the bathymetry. The reason is that symbolizing this data is difficult. This is because a color ramp that contains appropriate hues for both bathymetry and topography must be adjusted so that it shows the shoreline exactly in the right place, at zero elevation. Continue reading
In this post, Tom Brenneman and Rex Hansen share a control they created that allows you to automatically zoom to the results of a .Net Web ADF task.
This control, called ZoomToResults, enables you to automatically zoom to the result set returned from a task instead of requiring you to navigate through tree-view results in a standard TaskResults control. By default, this control is not visible at runtime. It is designed to simply zoom to the result set in the map if the number of features returned is less than the MaxResultsForMapZoom property. You will need to add this control to a task’s TaskResultsContainers collection to take advantage of these features. Note that this control must be listed before any other container in the collection (e.g. an out-of-the-box TaskResults control). This control was built with version 9.2, Service Pack 3 of the .Net Web ADF.
Follow these steps to use the control in your application.
- In Visual Studio, right click in the Toolbox and click Choose Items.
- Click Browse and navigate to ZoomToResults.dll and click OK.
- Drag the ZoomToResults control onto your web page.
- Set the following properties for ZoomToResults control:
MaxResultsForAutoSelect – this is the maximum result set that will be selected. The results will only be selected if a result set contains this value or less. Set this property to 0 to disable the auto selection capability.
MaxResultsForMapZoom – this is the maximum result set that will be zoomed to. The map will only be zoomed to the result set if it is less than or equal to this value. Set this property to 0 to disable the auto zoom capability.
MinWidthOfZoom – this is the minimum width (or height actually) in map units of the extent rectangle that will be zoomed to. This is particularly useful if the result set is a single point or a very small feature. In this case you could set the minimum extent that the map will zoom to. If you are working with geographic data you may want to make this significantly smaller than the default of 10.
ZoomExtentExpansionPercent – this is the expansion percentage around the extent of the result set for the map to zoom to. This is useful for defining a margin around the extent of features returned in a result set.
DisplayTaskResult – display task results like an out-of-the-box TaskResults control. By default, this property is false.
ShowTaskActivityIndicator – display activity indicator when a task is processing, like an out-of-the-box TaskResults control. By default, this property is false.
- To associate this container with a task, at design-time in design view click on the smart tag on the task and select Choose Task Results container.
- Click Add. Set the Name property of the new BuddyControl to the name of the ZoomToResult control (e.g. ZoomtoResults1).
- In the BuddyControl Collection Editor click the up arrow to move the ZoomToResults buddy control to the top of the list.
- Click OK to dismiss the BuddyControl Collection Editor.
- Try out the app!
Download the 9.2 control (The compressed folder contains the code with extensive comments from Tom and Rex, as well as a Readme file with the above instructions.)
Updated download for ArcGIS Server 9.3
By Charlie Frye, Esri Chief Cartographer
We’ve had a number of folks writing in on Ask a Cartographer wondering how to displace or offset coincident points so all the points could be seen. Data with coincident points is most commonly produced as a result of geocoding addresses. There are at least two ways to handle displaying this data. One would be to create a graduated or proportional symbol thematic map, and to do that the input point data would be processed with the Collect Events tool, which would produce output containing points that represented the locations and an attribute that indicated how many points were at that location. Continue reading
When you add the Business Analyst Online Reports Task inside ArcGIS Explorer, you gain access to a wealth of demographics and other information for any location or area in the United States. This Task tells you what satellite imagery cannot: how many people, houses and businesses are in your area of interest. Several free reports are included in the Task to give you easy access to Census 2000 demographic information. If you have an ArcWeb Services account, you can run additional reports, based on current year estimates and five-year projections for population and households.
Business Analyst Online combines GIS technology with extensive demographic, consumer, housing, and business data to deliver more than 70 presentation-quality reports and maps via your Web browser. ESRI hosts and updates the data annually to ensure wide access to the most current and accurate demographic data.
Business Analyst Online provides reports and maps to help you understand the people in your area as well as their lifestyle and buying behaviors. Other reports focus on the local housing and businesses in the area. Whether you are looking for suitable sites for your business expansion, or looking to attract new businesses to the area, Business Analyst Online content within ArcGIS Explorer helps create a compelling story.
By Charlie Frye, Esri Chief Cartographer
The Gulf of St. Lawrence map was originally created for an Esri tutorial on how to publish a map to ArcReader. The intent was to include a simple locator map with a few basic functions. These cartographic effects and tasks are highlighted:
Our team recently added a new tutorial to the Web-based help: Creating a Web Editing Application. It’s designed to help you set up a Web application for editing data, and uses the out-of-the-box Editing Task that comes with ArcGIS Server. Along the way, the tutorial discusses:
- How to configure an instance of Workgroup ArcSDE for Web editing
- How to design a map document that will be used in a Web editing application
- How to publish your map to ArcGIS Server
- How to create a Web application with the Editing Task
- How to use the application
Did this tutorial help you? Leave us a comment about your experience.
In an earlier post we talked about some of the new SDK features in the latest release (Build 410). In that post we mentioned the addition of OpenGL support and included a screenshot showing wind vectors implemented using OpenGL in Explorer. Here’s a link to a YouTube movie showing that in action.