Spike

A spike map is proportional symbol map, which is a type of thematic map that uses map symbols (spikes in this example) that vary in size to represent a quantitative variable.¹
Example below contains data about Covid cases in Czech Republic.

Example

Spike layer setting

Latitude

Longitude

Category

Value

Aggregation

Color

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Category colors

+−

Leaflet | Geovisto | VUT FIT Brno, © OpenStreetMap contributors © CARTO

Installation

npm i geovisto-layer-spike

Configuration

Configuration used in example above:

{
    "type": "geovisto-tool-layer-spike",
    "id": "geovisto-tool-layer-spike",
    "enabled": true,
    "layerName": "Spike layer",
    "data": {
        "latitude": "lat",
        "longitude": "long",
        "category": "data.category",
        "value": "data.value",
        "aggregation": "sum"
        "color": "#00FF00"
    }
}

Dimensions

Dimensions used in Spike Layer:

• latitude - latitude
• longitude - longitude
• category - main category to display
• value - value of category to display
• aggregation - value aggregation
• color - color of spikes

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¹ Wikipedia: Proportional symbol map