IMPORTANT: This document is specific to Sigma worksheets. To learn about this topic for Sigma’s new Workbooks feature, please visit Intro to Building Visualizations.

Summary of Content

Map Layers
      Layer Types
            Region Layers
            Latitude and Longitude Layers
            GeoJSON Layers
Create a Map
      Map by Region
      Map by Lat/Long Coordinates
      Map by GeoJSON

Map Layers 

Sigma’s map visualizations support multiple layers of data. You may choose to build just one layer or create multiple.

Creating layers allows you to visualize multiple sets of related location data on a single map.  Multiple layers of any combination of the layer types can be used on any map you create.

Layer Types

Maps support three distinct layer types: Lat/Long, GeoJSON and Region. The layer type(s) you select when building a map depend on a combination of the available data and the results you wish to see. For example, you may have a Text column ‘State’ with rows such as ‘Colorado and California’. To display these values, you would want to use a Region layer type.

Region Layers

Region layers require a single text column input to be defined on the Region Column field. Rows in this column should match one of the following Region Types: country, US states (name), US states (shortcode), US Counties (name, state name).

Examples:
Country - United States, China, Kenya, Brazil
US states (name) - Colorado, California, Massachusetts, Oklahoma
US states (shortcode) - CO, CA, MA, OK
US counties (name, state name) - Alemeda, California
      Note: The words 'County' or 'Parish' must be omitted from the county name. 

Latitude and Longitude Layers

Lat/Long layers require a number column input to be defined on both the Latitude and Longitude fields.  

GeoJSON Layers

GeoJSON layers require a variant column input to be defined on the GeoJSON Column field.
JSON blobs allow for storage of more complex geographical data than simple numeric lat/long columns. To plot a GeoJSON column on a map, the column must have a 'coordinates' key.

Example:  { "geometry": {"coordinates": [-94.042964, 33.019219] } } 

Pro-tip: If your GeoJSON data is stored as a text column (abc), you can convert it to a variant using Sigma's Variant function.

Create a Map

Map by Region

  1. Open the visualization tab in your worksheet’s right hand panel.
  2. Click on the + icon to add a new visualization.
    This will open up the visualization’s plot and format panel.
  3. Click on the map icon button under VISUALIZATION TYPE.
    Screen_Shot_2020-09-02_at_12.55.17_PM.png
  4. On the panel's Plot tab under Map Layer, select Region.
    Note: Selecting this Map Layer will create the first layer of your map. Maps may contain multiple layers of any of the three map layer types.
  5. Add a Text column to the Region Column field.
    Note: Data in this column should match your selected Region Type option in the field below. See examples.
  6. Select the Region Type that matches the data in your selected Region Column (eg Select ‘US States (Name)’ if your column contains rows such as ‘Colorado’ and ‘California’).
    Screen_Shot_2021-02-03_at_9.40.45_AM.png
  7. [optional] Add a column to the Color field, and select a color scheme from the dropdown palette.
    Screen_Shot_2021-02-03_at_9.41.15_AM.png
  8. [optional] Add a column to the Size field.
  9. [optional] Add one or more columns to the Detail field.
  10. [optional] Add another layer to your map by selecting an option from the 'Choose your new object type' menu at the top of the Plot tab.
    New layers are created below existing layers in the panel.

Map by Lat/Long Coordinates

  1. Open the visualization tab in your worksheet’s right hand panel.
  2. Click on the blue + icon to add a new visualization.
    This will open up the visualization’s plot and format panel.
  3. Click on the map icon button under VISUALIZATION TYPE.
    Screen_Shot_2020-09-02_at_12.55.17_PM.png
  4. On the panel's Plot tab under Map Layer, select Lat and Long Layer.
    Note: Selecting this Map Layer will create the first layer of your map. Maps may contain multiple layers of any of the three map layer types.
    Screen_Shot_2021-01-15_at_3.10.33_PM.png
  5. Add your latitude and longitude columns to the level's Latitude and Longitude fields.lat-long.gif
    Defining Latitude and Longitude values will automatically populate your map.
  6. [optional] Add a column to the Color field, and select a color scheme from the dropdown palette.
    Screen_Shot_2020-09-02_at_1.36.39_PM.png
  7. [optional] Add a column to the Size field.
  8. [optional] Add one or more columns to the Detail field.
  9. [optional] Add another layer to your map by selecting an option from the Choose your new object type menu at the top of the Plot tab. 
    New layers are created below existing layers in the panel. 

Map by GeoJSON

The following example uses a GeoJSON column to create a map. JSON blobs allow for storage of more complex geographical data than a numeric lat/long column. To plot a GeoJSON column on a map, the column must have a 'coordinates' key.
Example:  { "geometry": {"coordinates": [-94.042964, 33.019219] } } 

  1. Open the visualization tab in your worksheet’s right hand panel.
  2. Click on the blue + icon to add a new visualization.
    This will open up the visualization’s plot and format panel.
  3. Click on the map icon button under VISUALIZATION TYPE.
    Screen_Shot_2020-09-02_at_12.55.17_PM.png
  4. On the panel's Plot tab under Map Layer, select GeoJSON Object Layer.
    Note: Selecting this Map Layer will create the first layer of your map. Maps may contain multiple layers of any of the three map layer types.
    Screen_Shot_2021-01-15_at_3.10.33_PM.png
  5. Select your coordinate column from the level's GeoJSON column field.
    Defining the GeoJSON column field will automatically populate your map.
    Note: This column must be a variant column (represented as {i}). Text columns (abc) can be converted using Sigma's Variant function.
    geojson.gif
  6. [optional] Add a column to the Color field, and select a color scheme from the dropdown palette.
    Screen_Shot_2020-09-02_at_3.11.30_PM.png
  7. [optional] Add a column to the GeoJSON Line Width field.
  8. [optional] Add one or more columns to the Detail field.
  9. [optional] Add another layer to your map by selection an option from the 'Choose your new object type' menu at the top of the Plot tab. 
  10. New layers are created below existing layers in the panel.

 

IMPORTANT: This document is specific to Sigma worksheets. To learn about this topic for Sigma’s new Workbooks feature, please visit Intro to Building Visualizations.