Styling features on the map

This page describes how to style features in the Features Layer of the OS Maps for Power BI visual to create maps such as choropleths

Once you have added features to the Features Layer, you can control how they are displayed. You can control the colour of features according to values of a field from your Power BI data, or all together, as well as adjusting the opacity of features and size of any points present.

At present you can't vary the size of points in the Features Layer based on a field from your Power BI data. You can only do this for the Marker Points layer.

Feature display is controlled by selecting the "Features Layer" dropdown under the Symbology Settings pane of the Format Visual controls:

A screenshot of the Symbology Settings window

The controls that appear under this pane will vary depending what other data you have added to the visual. If you have not added any data to the Features Layer: Colour field, you will not see the "Min feature fill colour" and "Feature % clip" controls.

Varying the colour of features

The colour of features in the Features Layer is controlled in the same way as points in the Marker Points layer, so the instructions for the Marker Points Layer on the Styling Points on the map page apply equally to the Features Layer.

This allows you to create several different types of map:

• By mapping polygon features and adding a numeric field (or field summary) to the Features Layer: Colour field you will create a choropleth map.

• By mapping polygon features and adding another type of field, you will create a categorical (or chorochromatic) map. Categorical data in the Features Layer will be coloured according to the same process as in the Marker Points Layer.

If you have categorical data in both layers and choose to use default colours for both, then a different colour palette will be used for each layer to ensure that they can be distinguished

• Point and/or line features can also be symbolised with colours varying according to a numeric or categorical data field.

Controlling the appearance of unmatched features

If you have chosen to upload spacial data into the visual to populate the Features Layer, you may have features in your uploaded data which do not match any value provided in the data model through the field added to the Features Layer: Linking identifier field well.

If so, you can choose to include these unmatched features on the map. They will be styled using a single symbol, which you can configure using the Unmatched uploaded features dropdown pane of the Symbology Settings:

A screenshot of the Symbology Settings window

This allows a couple of advanced mapping features.

Firstly you could combine this with a slicer to create a map that allows interactive highlighting of a particular subset of features, whilst leaving all the other features visible:

A map configured to display buildings between 5-7 metres height as a choropleth, with other buildings also visible for context

Secondly, you could populate the features layer by using one of the other two means (via GSS codes or via geometry from the data model), and then upload a separate dataset which will then be entirely unmatched (because you are not adding data to the Linking Identifier field). This allows you to effectively display an entirely separate dataset for contextual information:

This map has been created by adding a WKT geometry field representing some buildings from the data model to the Features Layer: WKT or GeoJSON geometries field well, and styling it using a categorical field. A separate dataset representing site ownership polygons has been uploaded via the Upload Manager and is being displayed as unmatched data in grey. Both sets of features respond to pop-ups.