Problem Note 63482: The radius-based selection for a SAS® Visual Analytics geo map using Distance as the geographic selection type does not reflect the intended distance
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When a SAS Visual Analytics geo map uses Distance as the Geographic selection type, a radius-based selection might not calculate the correct distance. This issue is caused by distance distortion that occurs in map projections.
Most map projections are either equal-distant (equidistant) or equal-directional (equidirectional). This is the primary difference between a conical projection (equidistant) and a cylindrical projection (equidirectional). Projections of the entire earth are typically cylindrical such as the Mercator projection.
The results of a projection are linear distances from a known point. Those distances become more distorted the farther you get from 0,0 on the Earth in a Mercator projection.
The default OpenStreetMap background that is hosted by SAS is projected in Mercator. Mercator projection was selected so that SAS can provide location information anywhere in the world. Many projections, and the most accurate ones, are somewhat local in scope.
If you must use Distance as the Geographic selection type, consider changing the map background selection to a map with a different projection. For example, select a map that does not use a Mercator-based projection. Typically, local map projections reduce distance distortion.
If you are using Esri premium services, you can use Travel-distance instead of Distance as a workaround.
Operating System and Release Information
| Product Family | Product | System | Product Release | SAS Release | ||
| Reported | Fixed* | Reported | Fixed* | |||
| SAS System | SAS Visual Analytics | Cloud Foundry | 8.2 | 8.4 | Viya | Viya |
| Linux for x64 | 8.2 | 8.4 | Viya | Viya | ||
An update for this issue is available for SAS Viya 3.3. For instructions on how to access and apply software updates, see the Managing Your Software section of the SAS Viya 3.3 Administration document at
http://documentation.sas.com/?softwareId=administration&softwareVersion=3.3&softwareContextId=softwareUpdatesAn update for this issue is available for SAS Viya 3.4. For instructions on how to access and apply software updates, see the Updating Your SAS Viya software section in the SAS Viya 3.4 for Linux Deployment Guide at
http://documentation.sas.com/?softwareId=administration&softwareVersion=3.4&softwareContextId=softwareUpdatesAn update for this issue is available for SAS Viya 3.4. For instructions on how to access and apply software updates, see the Updating Your SAS Viya software section in the SAS Viya 3.4 for Windows Deployment Guide at
http://documentation.sas.com/?softwareId=administration&softwareVersion=3.4&softwareContextId=softwareUpdatesWinViya on Windows: An update for this issue is available for SAS Viya 3.4. For instructions on how to access and apply software updates, see the Updating Your SAS Viya software section in the SAS Viya 3.4 for Windows Deployment Guide at
http://documentation.sas.com/?softwareId=administration&softwareVersion=3.4&softwareContextId=softwareUpdatesWinViya on Linux: An update for this issue is available for SAS Viya 3.4. For instructions on how to access and apply software updates, see the Updating Your SAS Viya software section in the SAS Viya 3.4 for Linux Deployment Guide at
http://documentation.sas.com/?softwareId=administration&softwareVersion=3.4&softwareContextId=softwareUpdates| Type: | Problem Note |
| Priority: | high |
| Date Modified: | 2019-06-04 14:24:29 |
| Date Created: | 2019-01-14 17:45:45 |