# Choropleth map ![](../../_assets/datalens/heatmap.svg) in Yandex DataLens

A choropleth map uses different colors and hues for entire areas and regions. Areas on a map are set using geopolygons. 

A _geopolygon_ is an element that consists of an area bounded by a closed line and the line itself. The measure value is expressed through color saturation or hue.

​A choropleth map is used to analyze a measure within a territorial unit. For example, you can use a choropleth map to demonstrate the density of population of individual districts.

![choropleth-map](../../_assets/datalens/visualization-ref/choropleth-map/choropleth-map.png =800x)

To show polygons on a map, add a [Geopolygon](../dataset/data-types.md#geopolygon) type field to your dataset:

* Create a text field with data formatted as `[[[55.60807, 37.5698], [55.60847, 37.56992], [55.60851, 37.57095]]]` for polygon point coordinates enclosed in square brackets. 
    You can first prepare data in a database and set the [Geopolygon](../dataset/data-types.md#geopolygon) data type in the dataset description interface.
* Use the `GEOPOLYGON(polygon_string)` [function](../function-ref/GEOPOLYGON.md) to create a calculated field with the [Geopolygon](../dataset/data-types.md#geopolygon) data type.
* If your data contains a field with names of cities, regions, or countries, use the [geopoint/geopolygon reference](https://geointellect.com/files/geo_for_datalens.zip) by a Yandex partner Geointellect.

Follow the [link](https://storage.yandexcloud.net/doc-files/Regions.csv) to download a sample CSV file with Russian region polygons.

## Wizard sections {#wizard-sections}

Wizard<br/> section| Description
----- | ----
Polygons (Geopolygons) | Measure of the [Geopolygon](../dataset/data-types.md#geopolygon) type
Colors | Dimension or measure. Affects the color and intensity of area fill.
Tooltips | Dimension or measure. A tooltip that appears when you hover over an area. For `String` type fields, you can configure using basic [Markdown in Yandex DataLens](../dashboard/markdown.md) syntax: click the icon before the field name and enable **Markdown**.
Layer filters | Dimension or measure. Used as a filter for the current layer.
Filters | Dimension or measure. Used as a filter for the entire chart.

## Creating a choropleth map {#create-diagram}


{% note warning %}

If you use the new DataLens object model with [workbooks and collections](../workbooks-collections/index.md):


1. Go to the DataLens [home page](https://datalens.ru/?skipPromo=true). In the left-hand panel, select ![collections](../../_assets/console-icons/rectangles-4.svg) **Collections and workbooks**.


1. Open the workbook, click **Create** in the top-right corner, and select the object you need.

Follow the guide from step 4.

{% endnote %}


1. Go to the DataLens [home page](https://datalens.ru/?skipPromo=true).
1. In the left-hand panel, select ![chart](../../_assets/console-icons/chart-column.svg) **Charts**.
1. Click **Create chart** → **Chart**.
1. At the top left, click ![image](../../_assets/console-icons/circles-intersection.svg) **Select dataset** and specify the dataset to visualize. If you do not have a dataset, [create one](../dataset/create-dataset.md#create).
1. Select **Map** for the chart type.
1. Select **Polygons (Geopolygons)** as the layer type.
1. Drag a dimension of the [Geopolygon](../dataset/data-types.md#geopolygon) type from the dataset to the layer type selection section.
1. Color the polygons on the map. Move the measure or dimension to the **Colors** section.
1. Add tooltips to show the dimension and measure values when hovering over a polygon.

{% note info %}
              
You can show a particular area on the map using the **Center** and **Scale** [settings](../concepts/chart/settings.md#common-settings).
          
{% endnote %}

You can also:

* Add, rename, and delete a layer.
* Reorder the layers within a layer type.
* Apply a filter to the entire chart or one layer.

## Recommendations {#recomendations}

* Do not use a choropleth map to precisely compare some values.
* To make the comparison more precise, add data signatures or tooltips with information to the map.

#### See also {#see-also}

* [Creating a dashboard in Yandex DataLens](../operations/dashboard/create.md)
* [Adding a chart to a dashboard in Yandex DataLens](../operations/dashboard/add-chart.md)
* [Adding a selector to a dashboard in Yandex DataLens](../operations/dashboard/add-selector.md)