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Style location

Map Viewer allows you to explore your data in different ways through a variety of smart mapping styles. When you use Change Style in Map Viewer, the nature of your data determines the styling suggestions you see by default. Once you have decided how you want to present your layer, you can make changes to its appearance that are immediately reflected on the map. Map Viewer gives you control over styling elements such as color ramps, line weights, transparency, and symbols.

Sometimes you want to see where your features are located and how they are distributed geographically. Use the Location (Single symbol) style or, if you are mapping point features, the Heat map style, to see the location and distribution of features.

Location (Single symbol)

Drawing your data using a single symbol gives you a sense of how features are distributed—whether they're clustered or dispersed—and may reveal hidden patterns. For example, mapping a list of restaurant locations, you would likely see that the restaurants are clustered together in a business district.

See an example

To style location data using a single symbol, do the following:

  1. Follow the first four steps in the change style workflow.
  2. Click the Location (Single symbol) style and click Options.
  3. Do any of the following:
    • To change the symbol, click Symbols and change the settings. For more information, see Change symbols.
    • If you are mapping point symbols that have numeric information attached to the points—for example, the direction the wind is blowing—you can set a rotation angle based on that numeric attribute. You can also use a custom expression written in the Arcade scripting language to set a rotation angle.
    • If your layer streams updated feature observations from a streaming feature layer, you can select the option to draw a specific number of previous observations and select the option to connect the observations with a line.
    • To have Map Viewer calculate and set the optimal visible range, click Suggest next to the Visible Range slider. You can also manually set the visible range by moving the slider.
    • To change the transparency for the overall layer, move the Transparency slider to the left (less transparent) or the right (more transparent). To adjust the transparency of locations per feature, click Attribute Values, choose an attribute field, and optionally choose an attribute to divide by (for normalizing the data) and set precise transparency values. You can only use this option if you have numeric or date data associated with your locations. For example, if your layer contains income data, you could adjust the transparency of each location proportional to its income.
      Tip:

      You can also use a custom attribute expression written in Arcade when setting transparency for features. Arcade expressions are supported for all styles except Heat map, Predominant Category, Predominant Category and Size, and the Age styles. If the layer has an existing rendering expression, you can select it from the bottom of the drop-down menu. Optionally, you can edit the expression directly in Map Viewer by clicking the Edit Expression button and making changes in the editor window.

      In addition, you can create your own expression by selecting New Expression from the drop-down menu and using the editor window to create your expression, including giving it a name. If an expression was previously created for the layer for use in labels or pop-ups, you can use it to build your expression by selecting it from the Existing tab in the editor window.

Heat map

You can use heat maps when mapping the location of point features. Heat maps are useful when many of the points on the map are close together or overlapping, making it difficult to distinguish between features. They are very effective for displaying layers that contain a large number of points. For example, you can use a heat map to clearly show clusters of Starbucks coffee shops in Manhattan.

See an example

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 is best to avoid heat maps if you have only a few point features; instead, map the actual points.

Note:

If your data contains numeric attribute data, the heat map can weight this data to calculate the optimal display. Choose an attribute field with numeric data if you want to take advantage of weighted features. Strings and other nonnumeric data are not weighted. The attribute field name appears in the heat map options pane when it is being used for weighting.

To use a heat map to style your point data, do the following:

  1. Follow the first four steps in the change style workflow.
  2. Choose an attribute to show.
  3. Click the Heat Map style and click Options.
  4. Do any of the following:
    • To change how the colors are applied to the density surface, adjust the position of the two handles on the color ramp slider.
    • To make the clusters larger and smoother, or smaller and more distinct, adjust the Area of Influence slider.
    • To choose a different color ramp, click Symbols and change the settings. For more information, see Change symbols.
    • To calculate and set the optimal visible range, click Suggest next to the Visible Range slider. You can also manually set the visible range by moving the slider.
    • To change the transparency, move the Transparency slider to the left (less transparent) or the right (more transparent).
  5. Click OK when you are finished customizing your style or click Cancel to go back to the Change Style pane without saving any of your choices.