Advanced Mapping
1. Modifying Locations
>> Edit errors in geocode data
[Problem] Not all the counties are shown in the map
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Error: [Ambiguous] : same counties in other states have the same names
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Error: [Unrecognized] : typos (spelling errors)
[Fix the problems]
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Fix the ambiguous errors
- [Map] menu --> [Edit Locations]
- Fix the state to Washington
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Fix the typos (spelling errors)
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[Edit Locations] dialog box
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click the error and type the correct spelling
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>> Assign locations to data
[Mission] Add the location of each region’s corporate headquarters
[Problem] Values in the field are North, South, East, and West, which Tableau doesn’t have a default location for.
[Fix the problem] – Add specific locations
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Select the warning box --> Select [Edit Locations]
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match the data to specific values (match our regions to specific cities)
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Problem fixed
2. Customizing Geocodes for Addresses
When there are geographic fields that Tableau doesn’t recognize, you can assign your own Custom Geocodes to map your data.
[Mission] Map the various tour sites located around the city
[Problem] Tableau cannot recognize Street Address as geographic data
[Fix the problem] Custom geocode addresses by matching a street address to a specific latitude and longitude coordinate
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Generate the latitude and longitude coordinate with address using a batch geocoding website
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Create an excel spreadsheet (named as “Geocoded addresses”) which contains each Tour Site along with its matching latitude and longitude coordinate
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Add the data source “Geocoded addresses”
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[First] Start with the “Geocoded addresses” data source:
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[Rows] : Latitude
[Columns] : Longitude
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[Label] : [Tour Site]
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[Second] Switch to the original data source:
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blend two data sources with the common field [Tour Site]
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[Size] : [Number of Records]
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Add streets and highways into the map
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[Map] menu --> [Map layers]
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check the [Streets and Highways]
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3. Using a Background Image
We can use an background image and X/Y coordinates to show locations on a map
[Mission] Create an interactive map that shows the location of meeting rooms and their seating capacity in a company’s building
- Add a background image of an office layout, and
- Then plot the meeting room data on top of it
[Data]
- Room information and X / Y coordinates for each room
- Contains no X / Y coordinate values (NULL) for the room Woodland
[Process]
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Add [X] to [Columns]
Add [Y] to [Rows]
remove axis
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Add the background image
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[Map] menu --> [Background images] --> Data source name
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Add Image
- X Field: Left – 0, Right – 627 (pixels value)
- Y Field: Right – 0, Left – 673 (pixels value)
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Drag [Room Name] to [Detail]
Drag [Room Capacity] to [Size]
Set [Tooltip]
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Deal with the NULL data
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Right-click anywhere on the view --> [Annotate] --> [Point]
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Drag the annotation to the location of Room Woodland
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Update the room information file with Room Woodland’s X / Y coordinates
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Refresh the data source connection in Tableau by pressing F5
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Delete the annotation (coordinate tool) by selecting it and pressing the Delete key on the keyboard
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