Blazor Geographic High Density Map

In Blazor map component, you can use the IgbGeographicHighDensityScatterSeries to bind and show scatter data ranging from hundreds to millions of data points requiring exceedingly little loading time.

Blazor Geographic High Density Map Example

The demo above shows the IgbGeographicHighDensityScatterSeries series in the map component bound to hundreds or even thousands of data points representing Australia’s population density. The map plot area with more densely populated data points represented as coalescences of red pixels and loosely distributed data points by discrete blue pixels.

Because there are so many data points, the series displays the scatter data as tiny dots as opposed to full size markers, and displays areas with the most data using a higher color density representing a cluster of data points.

Data Requirements

Similar to other types of scatter series in the map control, the IgbGeographicHighDensityScatterSeries series has the DataSource property which can be bound to an array of objects. In addition, each data item in the items source must have two data columns that store geographic longitude and latitude coordinates and uses the LongitudeMemberPath and LatitudeMemberPath properties to map these data columns.

Data Binding

The following table summarizes the GeographicHighDensityScatterSeries series properties used for data binding.

Property	Type	Description
`DataSource`	any	Gets or sets the items source
`LongitudeMemberPath`	string	Uses the ItemsSource property to determine the location of the longitude values on the assigned items
`LatitudeMemberPath`	string	Uses the ItemsSource property to determine the location of the latitude values on the assigned items

Heat Color Scale

The Heat Color Scale, an optional feature, determines the color pattern within the series. The following table summarizes the properties used for determining the color scale.

Property	Type	Description
`HeatMinimum`	Double	Defines the double value representing the minimum end of the color scale
`HeatMaximum`	Double	Defines the double value representing the maximum end of the color scale
`HeatMinimumColor`	Color	Defines the point density color used at the bottom end of the color scale
`HeatMaximumColor`	Color	Defines the point density color used at the top end of the color scale

Code Example

The following code demonstrates how set the HeatMinimumColor and HeatMaximumColor properties of the IgbGeographicHighDensityScatterSeries

@using IgniteUI.Blazor.Controls

@inject HttpClient Http

<IgbGeographicMap Height="100%" Width="100%" Zoomable="true">
    <IgbGeographicHighDensityScatterSeries DataSource="DataSource"
        LongitudeMemberPath="Lon"
        LatitudeMemberPath="Lat"
        HeatMaximumColor="Red"
        HeatMinimumColor="10"
        HeatMaximum="5"
        HeatMinimum="0"
        PointExtent="1"
        MouseOverEnabled="true" />
</IgbGeographicMap>

@code {

    private List<AusPlaceCsv> DataSource;
    private Rect GeoBounds;

    protected override async Task OnInitializedAsync()
    {
        string url = "https://static.infragistics.com/xplatform/data/AusPlaces.csv";

        string csv = await Http.GetStringAsync(url);

        string[] csvLines = csv.Split(Environment.NewLine);

        List<AusPlaceCsv> dataItems = new List<AusPlaceCsv>();

        for (int i = 1; i < csvLines.Length - 1; i++)
        {
            string[] columns = csvLines[i].Split(",");
            AusPlaceCsv location = new AusPlaceCsv()
            {
                Lat = double.Parse(columns[2]),
                Lon = double.Parse(columns[1]),
                Name = columns[0],
            };

            dataItems.Add(location);
        }

        this.DataSource = dataItems;

        await Task.Delay(1);
    }

    public class AusPlaceCsv
    {
        public string Name { get; set; }
        public double Lat { get; set; }
        public double Lon { get; set; }
        public double Pop { get; set; }
        public string Country { get; set; }
        public bool Cap { get; set; }
    }
}

Blazor Geographic High Density Map