Geocoding in FoodChain-Lab

Tasks

• Perform a geocoding by using the Geocoding workflow from https://github.com/SiLeBAT/BfROpenLa….
• Use “Street”, “HouseNumber”, “City” and “Country” as input parameters.
• Do the geocoding by using the MapQuest Geocoding Service.

Step 1

• Import the Geocoding workflow from https://github.com/SiLeBAT/BfROpenLa….
• In this tutorial we are using the MapQuest Open Geocoding service.

Step 2

• For using MapQuest you have to register and create a key at https://developer.mapquest.com
• This key has to be entered in the KNIME preferences.
• Select File < Preferences in the menu bar.

Step 3

• The Preferences dialog will pop up.
• Here you can specify all preferences for KNIME and FoodChain-Lab.

Step 4

• Select KNIME < Geocoding in the navigation tree on the left.
• Enter your MapQuest Application Key and press OK.

Step 5

• To perform geocoding we need one column with addresses in our data table. The Supply Chain Reader puts out all parts of the address (street, city, …) in different columns.
• The address column is created via the Address Creator node.
• Double click on this node to open its dialog.

Step 6

• In the dialog you can specify the columns that should used for creating the address column.

Step 7

• Since we want to do the Geocoding based on “Street”, “HouseNumber”, “City” and “Country”, we have to set the Country Column to “Country” and the Postal Code Column to “none”.
• Press OK to close the dialog.

Step 8

• Since we changed the settings, the node resets automatically.
• Press OK.

Step 9

• The configuration for the Address Creator has been updated.

Step 10

• Right click on the Address Creator node and select Execute.

Step 11

• Now that we updated the Address, the geocoding can be set up.
• Double click on the Geocoding node to open its dialog.

Step 12

• Here you can specify the Service Provider for geocoding and the column that should be used.
• Both are already correctly set, so we don’t need to change anything here.

Step 13

• For many requests geocoding services return multiple results (e.g. when there are two streets with the same name).
• To deal with this we have to decide if we just want to use the first or look at all choices and try to find the best.
• Looking manually at all choices is a lot of work for large data sets. In this tutorial select Use first and press OK.

Step 14

• Right click on the Geocoding node and select Execute.

Step 15

• The execution can take a while.
• The progress bar under the node shows what percentage of data has been processed.

Step 16

• When the execution is finished, we can look at the results.
• Right click on the Geocoding node and select Coordinates.

Step 17

• In the dialog that pops up, you can look at the whole data table.

Step 18

• Scroll to the right to look at the columns with latitude and longitude (the two rightmost columns).
• Some geocoding requests were not successful. MapQuest returned US coordinates, although all addresses are in Germany.