Create a Cluster map

When you have a layer with several overlapping geometries on the map at a higher zoom level, you may find it useful to create a cluster layer. This type of layer is a map viewer option that allows you to group multiple contiguous geometries into a single point.

Follow these steps to build your Cluster map:

1) Download the Tree inventory Shapefile from the City of Guelph, and import it into your eVouala account;

http://data.open.guelph.ca/dataset/tree-inventory

2) Create a map with this Data Source, then click "Edit template" in the properties of the Data Source in the Layer tree;

3) Replace these two variables:

* @styleitem
* @classes

With this mapping script:

## Step 1 - Add Cluster configuration options
CLUSTER
  MAXDISTANCE 22 # in pixels
  REGION "ellipse" # can be rectangle or ellipse
END
## Step 2 - Configurate the Cluster display
CLASS
  EXPRESSION ([Cluster_FeatureCount] > 1)
  NAME 'More then 1'
  STYLE
    COLOR '#31a354'
    SYMBOL 'circle'
    OPACITY 75
    OUTLINEWIDTH 0.5
    OUTLINECOLOR '#eff3ff'
    SIZE 20
  END
  LABEL
    TEXT "[Cluster_FeatureCount]"
    SIZE 8
    COLOR '#FFFFFF'
    OUTLINEWIDTH 2
    FONT 'mu'
    POSITION CC
    TYPE truetype
  END
END
## Step 3 - Configurate the points display ...
CLASS
  EXPRESSION ([Cluster_FeatureCount] = 1)
  NAME 'Single tree'
  STYLE
    COLOR '#31a354'
    SYMBOL 'circle'
    OUTLINEWIDTH 0.5
    OUTLINECOLOR '#eff3ff'
    SIZE 7
  END
END

Et vouala!