Maps are powerful because they help you gain a deeper understanding of your data by allowing you to visualize it in many ways. For example, population data for countries can be visualized as a sequence of colors, such as from light to dark, or as graduated circles, such as from small to large. This flexibility allows you to tell different stories and discover hidden patterns depending on how the data is presented. But because mapmaking is flexible, it requires you to make decisions when there isn't always a single best answer.
Fortunately, for any given data or layer, ArcGIS Maps for Power BI allows you to explore styling options using smart mapping defaults.
The styling choices that are available when you click Map theme are determined by the data you're mapping. For example, you'll see different styling choices if your map layer is composed of points rather than boundary locations, such as heat map styling options for a layer composed of points but not for a boundary layer such as U.S. states or ZIP Codes. The styling options are also determined by the type of data associated with the locations in the layer. For example, a point may have location information such as geographic coordinates but may also have categorical information such as retail location type, or numerical information such as sales details. Not every styling type can be used for every data type. By analyzing these and other characteristics of your layer, ArcGIS Maps for Power BI presents the best styling choices.
You can change the symbology for data layers only. You cannot change the symbology for reference layers.
To change the map theme, complete the following steps:
- Open a map-enabled report or create a new one. If necessary, place the report in Author mode.
- In the Layers list, click Layer options on the data layer you want to modify and choose Symbology.
The Symbology option appears only on layers created using Power BI data.
The Symbology pane appears, listing available options based on the nature of the layer's data.
- Expand the Map theme category.
A map theme gallery opens, showing thumbnails of available map styles. Different styles are presented based on the field data values in your map. Only the options that apply to the field values in your map appear. For example, if you only added a location field to your map, available drawing styles include Location Only and, for point layers, Heat Map and Clustering. If you specify a field that contains numeric data, you can choose from themes available for location data and several other themes.
Different map themes are available depending on the fields added to the map. Hover over the Information button to view a brief description of the theme.
- Click a map theme to select it.
The map automatically displays the new theme.
The map themes in ArcGIS Maps for Power BI are described below.
Style location data using a single symbol. This theme shows each location on the map using the same symbol.
You can use heat maps to visualize the density of points on a map. Heat maps are useful when many of the points on the map are close together or overlapping, making it difficult to distinguish between locations. They are also effective for displaying layers that contain a large number of points.
Heat maps use the points in the layer to calculate and display the relative density of points on the map as smoothly varying sets of colors ranging from cool (low density of points) to hot (many points). It's best to avoid heat maps if you have only a few locations; instead, map the actual points.
Optionally, drag a numerical value into the Size field well to better define the heat map properties.
Tooltips are not available in heat map layers.
Also, because a heat map uses a specified color ramp to render point density, a value placed in the Color field well is ignored.
When a layer contains a large number of points, showing each location individually on the map is often not useful. In this scenario, points often overlap, making it difficult to distinguish between locations. When they do not overlap, it's usually difficult or impossible to visually extract meaningful information when hundreds or thousands of points are shown at once.
One approach to resolving this issue is to group point locations within a certain distance of one another on-screen into one symbol. This is known as clustering. Because the clustering is dependent on screen distance, more points are aggregated into fewer groups as you zoom out. Conversely, points are divided into more groups as you zoom in. When you zoom to a level where the clustering area around a point no longer contains any other locations, that point will not be clustered but rather will be shown in its location using the styling specified by the layer.
If you style a point layer using fields grouped by category—such as store type, for example—the clusters will display a pie chart showing the ratio of categories within that cluster. As you zoom in, the cluster is divided into smaller groups, and the pie chart changes to reflect the information in the new cluster. The value placed in the Color field well must be a string or unique value.
Note:For layers styled using the Clustering map theme, pop-ups and selection tools are not available.
This map theme uses graduated symbol sizes to represent your numerical data or ranked categories, allowing you to visually compare quantities and identify trends. In these proportional symbol maps, larger symbols represent larger numbers. Adjust the size of the symbols to clarify the story you're telling. For example, you can use graduated symbols to show store revenue. Add a numerical field value to the map visualization's Size field well to enable this theme.
If your mapped locations are represented by polygons and you place a numeric value in the Size field well, the map updates to show graduated symbols, with the symbol placed in the center of the area defined by the original polygon.
If your data is numeric, you may want to distinguish map locations based on a color ramp. Different types of color ramps can be used. For example, a simple light-to-dark color ramp is good for showing low-to-high data values such as age, income, or ratio. Color ramps like this can be applied to points or boundaries. For example, you can use a light-to-dark color ramp to show store profits.
If you have categorical data, you can style locations by specifying different colors for each category. Add a field value to the map visualization's Color field well to enable this theme.
Size & Color
With this theme, you choose two field values in your data and finalize both the size and the color of point symbols on your map. Or, you can use the same field twice: to set the size of the symbols, and to set the colors, based on the part of the data you want to emphasize. When you have numeric data, this is a good style to use to show count information, such as the number of female single-parent households, shaded by a rate.
To style your map by size and category, drag a categorical data field into the Color field well.
You can also use this style if your data contains date values that you want to show sequentially as a continuous timeline on the map along with another field. If you add a date field value to the Color field well, color is used to show the date values, while proportional symbols are used to show the value in the Size field well. If you place the date value in the Size field well, the reverse is true: dates are shown using proportional symbols and color is used to show the other field value.