Polyline map

A polyline map is a type of geolayer on a Map chart that lets you draw polylines on the map. A polyline consists of points connected in a certain order. A polyline map is used, for example, to show the path of a moving object.

To build a polyline map, you need the following data:

• Coordinates of line points of the Geopoint data type. Each point of each polyline must be stored in a dataset as a separate row.
• A field or a set of fields to group points into lines (each line's ID).
• A field to sort the order of points in each line (such as a timestamp or point number).

You can color polyline segments in one of the following ways:

• In a gradient by measure (for a example, an average speed in a point).

  

• In discrete colors by dimension (for example, by trip name).

  

Sections in the wizard

Section in the wizard	Description
Polylines (Geopoints)	Measure with the type Geopoint.
Measures	Measure. The value displayed when you hover over a point.
Grouping	Dimension. Defines a group of points forming a polyline.
Colors	Dimension or measure. Affects the intensity of line segment fill. A segment is filled in from the originating point.
Order	Dimension. Defines the order for connecting points within a group.
Layer filters	Dimension or measure. Used as a filter for the current layer.
Chart filters	Dimension or measure. Used as a filter for the entire chart.

Creating a polyline map

To create a polyline map:

1. On the DataLens home page, click Create chart.
2. Under Dataset, select a dataset for visualization.
3. Select the Map chart type.
4. Select the Polylines (Geopoints) layer type.
5. Drag a dimension with the Geopoint type from the dataset to the layer type selection section.
6. Specify a group of points that defines polylines. Move the measure to the Grouping section.
7. Define the order for connecting points within the group. Move the measure to the Order section.
8. Color the line on the map. Move the measure or dimension to the Colors section.

You can also:

• Add, rename, and delete a layer.
• Apply a filter to the whole chart or one layer.

Recommendations

• Reduce the number of route points at the source level if there are too many of them. To do this, use a chart-level filter. This will speed up map loading and rendering.
• Use the MAVG moving average function to smooth measure outliers of individual points/sections. For example, when building a line to represent the average speed using the MAVG([speed],2,2) function, the speed measure values are averaged in the current, two previous, and two subsequent points. As a result, the color gradient changes more smoothly.