The Data Inspector Library allows you to assess the coverage of your datasets stored in the HERE platform across partitions both on global and local scales. You can see where your partitions are located on a map and figure out the geographical distribution of your data based on tile size.
The partition coverage map reflects the geographical availability of partitions. The coverage map is always rendered as an overlay on top of the basemap for all HERE-Tiled versioned and volatile data layers.
The partition size heatmap represents the size of data contained in every tile with related color gradients. The size heatmap is only applicable to HERE-Tiled versioned data layers.
You can analyze the coverage of your datasets through the HERE platform portal. For this, browse to the catalog layer you need and select the Inspect tab. Then, in the upper-left corner of the Data Inspector, click the Control Panel button to display the Heatmap panel. For more details on the coverage rendering rules, see the chapters below.
You can also embed coverage with aggregated data and size heatmaps in your Data Inspector Library-based applications. For this, use the
CoverageControls component in combination with the
CoverageDataSource with the
AggregatedCoverage mixin applied, as in the example below:
const coverageClass = AggregatedCoverage(CoverageDataSource); const coverageDataSource = new coverageClass(config);
To use this feature with the
DataInspector, enable two of the options below:
enableCoverage: true, enableExtendedCoverage: true,
You can see how the coverage maps and size heatmaps work in the Data Inspector Library examples –
control / DI and
interactive / DI / full.
The way coverage data and tile size data are visualized at a certain map zoom level depends on a layer’s data level.
To learn the level at which data is stored in a layer, do either of the following:
- In the Data Inspector's Control Panel, view Data level.
- In the HERE platform portal, go to the layer’s details page and consult the layer’s Zoom Levels property.
In the OLP CLI for the HERE platform, run the command
olp catalog layer show <catalog HRN> <layer ID> [command options]and consult the
property. For more information on this option, go to the Layers chapter of the Command Line Interface Developer Guide.
For the Data Level – 3 range (inclusively), the most up-to-date, non-aggregated tile coverage and size data are shown. For example, the data level of the Roads - Topology & Geometry layer in the HERE Map Content catalog is 12. You can zoom out up to the level 9 and still be able to view the freshest tile coverage and size data.
The coverage map, in this case, is rendered as a grid with explicit tile borders.
To turn on the size heatmap, in the Heatmap panel, click the eye button.
For the Data Level - 3 range, all the controls in the Heatmap panel are enabled:
Color scale: Shows a palette of color gradients that represent various partition sizes on the heatmap. Partition size values at the top of the color scale show the smallest and the largest partitions in the entire layer. By default, the size values are aggregated on a global scale.
Show local maxima: Allows you to change the scale of the size heatmap from global to local. On the local scale, the color scale shows the sizes of the smallest and the largest partitions that are currently visible in the Map View.
Opacity: Allows configuring the opacity of the size heatmap overlay in relation to the basemap.
For the Data Level + 4 & up range, the partition coverage and size data are aggregated from the underlying partitions. In this mode, the aggregated data is precalculated on a daily basis for each HERE-Tiled layer. For volatile layers, only coverage data is precalculated. Therefore, the coverage and size data shown on these higher zoom levels is at least 24 hours outdated. For more information on the HERE-Tiled partitioning schema, see the Partitions chapter of the Data API Developer Guide.
Now let's go back to our Roads - Topology & Geometry layer example in the chapter above. If you zoom out this layer to the 7th level and up, you can view the slightly outdated, approximate coverage and size data.
The coverage map, in this case, is rendered as a grid with implicit tile borders and shows aggregated data coverage. If at least one of the underlying child partitions contains data, aggregated rectangles on the coverage overlay are rendered.
If you click the eye button, the size heatmap is shown as a color map for aggregated tile data. The aggregation mechanism sums the sizes of all underlying child tiles and renders aggregated rectangles on the size heatmap.
For the Data Level + 4 & up range, the color scale always represents the global scale, and, therefore, the Show local maxima checkbox is disabled.