GIS Location Data¶
In some applications, there is a wizard question if geo-code data should be retrieved from a third-party provider (Location IQ). If this option is activated, the page GIS Location Data becomes part of the workflow. The purpose of this page is to help the user inspect and adapt the data to get the correct coordinates for the locations.
In order to use this, you need to provide these attributes: * Street * City * State * Postal Code * Country
The Country attribute is mandatory, while in general it would be good to have at least City or Postal Code, and state if that is relevant for that country.
Once you open the page, you see the locations for which the coordinates are still needed, via checkbox Request Geo-code, in table Location Data. You can retrieve the Geo-coordinates via the page action Retrieve Geo-coordinates for all location. This uses the Street, City, Postal Code, State, and Country to obtain the coordinates, together with more details on that location. Once you have inspected those results, you need to save them via the Save Location Data page action menu. This saves the data so that it can be retrieved the next time you are loading this Excel file.
This map displays all locations based on their coordinates. The location selected in the map or in table Location Data is highlighted in green. It can help you to inspect the solution provided by the geo-coding service. If a location has not been geo-coded, Data Navigator shows a red circle in the center of the earth, an visual indicator that data is still missing.
The table contains all locations together with detailed information on this location. There are three types of data in this table:
- A checkbox to indicate if geo-code data needs to be retrieved. (The number of locations for which data is still needed is available in the header.)
- The input data that describes this location: Street, City, Postal Code, State, and Country. This data can be edited if that is needed to get better results.
- Output data from the geo-code service. This includes Longitude, Latitude, importance, Size, Count, Name, Class, Type, Date.
- Importance: According to Location IQ Calculated importance of this result compared to the search query the user has provided. Ranges between 0 and 1. (Source: https://locationiq.com/docs). Where 1 is best, and 0 the worst.
- Size: A measure of the size of the location. The smaller this value is, the smaller the region is that describes the location. This value is larger if you are geo-coding a country but should be smaller if you are geo-coding a city.
- Count: The number of geo-coordinates that are returned for this one location.
Once Data Navigator has retrieved the coordinates of the locations, you need to review the results to make sure they are correct. In most cases the results with an Importance of 0.3 or higher are correct. In case the value is lower, you should inspect the results in more details. You can check to see if the size is comparable to similar location, and if the Name, Class and Type make sense.
The geo-code service can return multiple places. The model picks the one with the highest importance, but it shows alternative places as well. In the map and table on the left part of the screen, you see details of the alternative places with respect to the location selected in the right part of the screen. In the map, you see those alternative places. The node that is used in the table on the right is marked in green, and the selected node is marked in orange. In this map, you also see a green rectangle. This is the smallest box that covers the complete location. The size that was mentioned earlier, is the length of the diagonal in kilometers.
The data in the table is the same as in Location Data table, see above, but now for alternative places.
Once you select a node in the map or a row in the table, you can click the right mouse menu Use this place instead. In that case, this place is used in the table on the left and going forward.
As mentioned before, it is important to click the Save Location Data page action, so that this data is stored. Only after you click this, the page will get the completed check-mark in the workflow.