Geometries
Getting your data on the map
Geometries are geometric properties in data allowing data to be visualized on a map. They refer to geographical data provided in a GeoJSON file. Akuko provides a number of different ways to generate geometries from a data source so they can be visualized. Geometries can be represented as:
- Points (Circles): Made up of latitude and longitude coordinates.
- Lines: Expressed through 2 connected points.
- Polygons: Made up of multiple points joined to denote an area.
Go to the Geometries tab in your data source and click Add Geometry. You will be given two options to create a geometry: Latitude / Longitude or Join.
One of the most common ways to represent the locations of places is with GPS coordinates, latitude and longitude. The use of GPS coordinates is convenient as latitude and longitude can be represented in a text format and included in tabular data.
To add a geometry using GPS points, ensure the data you have uploaded has at least one set of latitude and longitude columns.
When creating a geometry, give your geometry a Name. Pick a name that is descriptive enough in case your data source has multiple geometries. Then, select the Latitude / Longitude as the Type and pick the fields that correspond with the latitude and longitude columns in the source.
X and Y Coordinates
Many times your GPS data will come in X and Y format. In this case, it is helpful to think of a chart with an X and Y axis, where Y is North/South and X is East/West. A GPS point with a higher Y value will be farther north on your map than a point with a lower Y value. Or in simple terms:
- Latitude - Y
- Longitude - X
You want your map to load fast and efficient bandwidths. Optimizing the amount of data your data source's geometry sends to a map will help achieve faster loading and efficient bandwidths. To select the data available on the map, select the properties from the data source and add them as properties. You add new properties at any time. Try to avoid adding any properties not needed for your visualizations. This will keep your maps loading fast and make the process of selecting properties when building map layers a lot easier.
Since the latitude and longitude are included in the geometry, you do not need to include them again in your properties, unless you want to say display the GPS coordinates in a pop-up.
When you are ready, click Create.
After a few seconds, your geometry should update, and you should see a unique ID and green check mark indicating your geometry was successfully created.
If your data has changed or you would like to add a new property, you will need to click Update to update your geometry.
Once this is complete, you can now create a map. Add a map layer from this data source and visualize it.
When visualizing data in maps, one of the most common things you will want to do is to visualize a dimension or measure from your tabular data to corresponding locations on a map. For example, you may want to visualize happiness by country as rated by the World Happiness Report.
Akuko makes this easy by allowing you to join data from one data source to the geometry of another data source. Joining data ensures that you not only have names of places but also other key details like population size, p-codes, or health facility services provided.
To join data, go to Geometries, click Add Geometry, and select the Join type. Ensure you also enter a name for your geometry.
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Select the data source that contains data you want to visualize.
The Source Join is the column in your datas source, whereas the Target Join is the column in your GeoJSON file. The fields in both the source and the target need to have the same type for the join to work. Select the name of the field in your data source you want to join against the target. In the example below, the region from the COVID projection map is being joined against the status field from the Mercator Projection Map.
Similar to creating a geometry with GPS coordinates, select the properties you want from the data source, and click Create.
After a few seconds, your geometry should update, and you should see a unique ID and green check mark indicating your geometry was successfully created.
Once generated, the data source can now be added to a map and visualized. In the example below, the map shows happiness by country.
Currently, you can only add data properties from the data source and NOT the data source with the geometry you are joining against.
There will be cases when you will want to visualize your data in a time series or with a group by period. In this example, there is a row per county for each day of estimates cases.
Estimated Covid-19 cases in Chittenden County by date
To be able to visualize this data as a time series on the map, you need to use the group by feature in Advanced options in the geometry management component.
Pick the value you want to group by, like
date as in the example, and the values you want to visualize in the time series, like estimated_cases for the below example. The group by feature can be applied to any other use case where you have multiple rows of data for the object you want to visualize against.
Last modified 1yr ago