Note:
This topic includes information related to Map Viewer Classic. An enhanced map viewer is now available. Open Map Viewer from the app launcher to get started. To learn more, see the Map Viewer help documentation.
Map Viewer Classic allows you to explore your data through a variety of smart mapping styles. When you use Change Style in Map Viewer Classic, the nature of your data determines the styling suggestions you see by default. Once you decide how you want to present the layer, you can make changes to its appearance that are immediately reflected on the map. With Map Viewer Classic, you have control over styling elements such as color ramps, line weights, transparency, and symbols.
Several styling options are available for visualizing features according to time and date values.
Continuous Timeline (Color)
If your layer contains date values, you may want to use color to view your data sequentially from new to old or before and after a key date. For example, applying a color ramp to the date attribute in your streets feature layer can help you see which street segments in your city were inspected most recently and which ones are due to be inspected again. See an example.
Note:
This style is available for hosted feature layers, feature collections, and CSV layers.
To style dates using color to show a continuous timeline, do the following:
- Follow the first four steps in the Change style workflow.
- Choose an attribute to show. For this mapping style, choose an attribute that contains date values.
- Click the Continuous Timeline (Color) style and click Options.
- Do any of the following:
- Choose a theme for the color ramp. Each color theme option can tell a different story by matching colors to your data in different ways.
- To change how the color ramp is applied to the data, adjust the bounding handles along the color ramp. You can either drag the handle or click the date beside the handle and type a new date. Experiment with the position of the handles and use the histogram and calculated average
to understand the distribution of the data to fine-tune the message of the map. - To invert, or flip, the colors in the color ramp, click Invert.
- To choose a different color ramp, or to change other graphic parameters such as stroke weights and colors, click Symbols and choose the settings you want. For more information, see Change symbols.
- To see details in the histogram more closely, click Zoom in.
- If you are mapping point symbols, you have the option to rotate symbols based on a second numeric field. For example, the color of the points could depict air temperature at weather stations, while the rotation of the points depicts humidity. The default symbol is round, which doesn't depict rotation very well. It is best to choose a different shape.
- To draw locations with missing data on the map, check Draw features with no value. Uncheck it to hide the features.
- To hide the color ramp in the legend, uncheck the Show in legend box.
- To change the transparency, move the Transparency slider to the left (less transparent) or the right (more transparent). To adjust the transparency per feature, click Attribute Values, choose an attribute field, optionally choose an attribute to divide by (for normalizing numeric data only), and set precise transparency values. You can only adjust per feature if you have date or numeric data associated with your locations. For example, if your layer contains population data, you could adjust the transparency of each location proportional to its population. If you want to hide the transparency ramp in the legend, uncheck the Show in legend box.
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 Classic by clicking the Edit Expression button and making changes in the editor window.
In addition, you can create a custom expression by selecting New Expression from the drop-down menu and using the editor window to create the 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 the expression by selecting it from the Existing tab in the editor window.
- To calculate and set the optimal visible range, click Suggest next to the Visible Range slider. You can also manually set the visible range.
- 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.
Continuous Timeline (Size)
If your layer contains date values, you can use a sequence of proportional symbols to view the dates sequentially on the map. For example, in a map showing furniture sales, you could show where recent sales are occurring using larger symbols to represent more recent sales and smaller symbols to represent less recent sales. See an example.
Note:
This style is available for hosted feature layers, feature collections, and CSV layers.
To style dates using proportional symbols to show a continuous timeline, do the following:
- Follow the first four steps in the Change style workflow.
- Choose an attribute to show. For this mapping style, choose an attribute that contains date values.
- Click the Continuous Timeline (Size) style and click Options.
- Do any of the following:
- To change the styling of your proportional symbols (color, stroke, opacity), click Symbols and change the settings. For more information, see Change symbols.
- To change how the proportional symbols are applied to the data, adjust the bounding handles along the histogram. You can either drag the handle or click the date beside the handle and type a new date. All values above the upper handle are drawn with the same largest symbol. Values below the lower handle are displayed with the same smallest symbol. The remaining values in between are drawn with a proportional sequence of sizes between the two bounds. Experiment with the position of the handles and use the histogram to see the distribution of the data to fine-tune the message of the map.
- To invert the symbol size order, click Invert.
Note:
By default, recent dates are drawn with larger symbols and less recent dates are drawn with smaller symbols. Clicking Invert allows you to reverse this pattern.
- To adjust the size of the symbols, choose a minimum and maximum Size in pixels.
- If you are mapping data associated with polygons, choose to adjust the size range automatically or specify the size range. For the automatic option, the symbols are optimized for the initial map zoom level and will automatically adjust so they look better across more zoom levels.
- To see details in the histogram more closely, click Zoom in.
- If you are mapping data associated with polygons, click Polygons to adjust the fill and stroke properties of the polygons.
- To draw locations with missing data on the map, check Draw features with no value. Uncheck it to hide the features.
- If you are mapping point symbols, you have the option to rotate symbols based on a second numeric field. For example, the color of the points could depict air temperature at weather stations, while the rotation of the points depicts humidity. The default symbol is round, which doesn't depict rotation very well. It is best to choose a different shape.
- To hide the size ramp in the legend, uncheck the Show in legend box.
- To change the transparency, move the Transparency slider to the left (less transparent) or the right (more transparent). To adjust the transparency per feature, click Attribute Values, choose an attribute field, optionally choose an attribute to divide by (for normalizing numeric data only), and set precise transparency values. You can only adjust per feature if you have date or numeric data associated with your locations. For example, if your layer contains urban areas, you could adjust the transparency of each location proportional to its size. If you want to hide the transparency ramp in the legend, uncheck the Show in legend box.
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 Classic by clicking the Edit Expression button and making changes in the editor window.
In addition, you can create a custom expression by selecting New Expression from the drop-down menu and using the editor window to create the 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 the expression by selecting it from the Existing tab in the editor window.
- To calculate and set the optimal visible range, click Suggest next to the Visible Range slider. You can also manually set the visible range.
- 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.
Age (Color)
If your layer contains date or time values, you may want to use color to represent the age of features. Age reflects the length of time (in seconds, minutes, hours, days, months, or years) from a start date or time to an end date or time. For example, by applying this style to a parcels layer using the sale date attribute and the current date to specify the period of time, you can use color to show which homes in a neighborhood were sold more than 15 years ago and which were sold more recently. See an example.
Note:
This style is available for hosted feature layers, feature collections, and CSV layers.
To style dates using color to show age, do the following:
- Follow the first four steps in the Change style workflow.
- Choose an attribute to show. For this mapping style, choose an attribute that contains date values.
- Click the Age (Color) style and click Options.
- From the To drop-down menu, select an end date. Click the Switch Attributes button
if you want to switch the start date to the end date. - From the Units drop-down menu, select the time units you want to use.
- Do any of the following:
- Choose a theme for the color ramp. Each color theme option can tell a different story by matching colors to your data in different ways.
- To change how the color ramp is applied to the data, adjust the bounding handles along the color ramp. You can either drag the handle or click the number beside the handle and type a precise value. Experiment with the position of the handles and use the histogram and calculated average to understand the distribution of the data to fine-tune the message of the map.
- To invert, or flip, the colors in the color ramp, click Invert.
- To choose a different color ramp, or to change other graphic parameters such as stroke weights and colors, click Symbols and choose the settings you want. For more information, see Change symbols.
- To see details in the histogram more closely, click Zoom in.
- If you are mapping point symbols, you have the option to rotate symbols based on a second numeric field. For example, the color of the points could depict air temperature at weather stations, while the rotation of the points depicts humidity. The default symbol is round, which doesn't depict rotation very well. It is best to choose a different shape.
- To draw locations with missing data on the map, check Draw features with no value. Uncheck it to hide the features.
- To hide the color ramp in the legend, uncheck the Show in legend box.
- To change the transparency, move the Transparency slider to the left (less transparent) or the right (more transparent). To adjust the transparency per feature, click Attribute Values, choose an attribute field, optionally choose an attribute to divide by (for normalizing numeric data only), and set precise transparency values. You can only adjust per feature if you have date or numeric data associated with your locations. For example, if your layer contains population data, you could adjust the transparency of each location proportional to its population. If you want to hide the transparency ramp in the legend, uncheck the Show in legend box.
- To calculate and set the optimal visible range, click Suggest next to the Visible Range slider. You can also manually set the visible range.
- 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.
Age (Size)
If your layer contains date or time values, you can use a sequence of proportional symbols to view the age of features. Age reflects the length of time (in seconds, minutes, hours, days, months, or years) from a start date or time to an end date or time. For example, if you want to show the age of code violations from complaint date to compliance date, you can show violations that are less than 30 days old with a small symbol and use increasingly larger symbols for violations that are closer to 90 days old. See an example.
Note:
This style is available for hosted feature layers, feature collections, and CSV layers.
To style dates using proportional symbols to show age, do the following:
- Follow the first four steps in the Change style workflow.
- Choose an attribute to show. For this mapping style, choose an attribute that contains date values.
- Click the Age (Size) style and click Options.
- From the To drop-down menu, select an end date. Click the Switch Attributes button if you want to switch the start date to the end date.
- From the Units drop-down menu, select the time units you want to use.
- Do any of the following:
- To change the styling of your proportional symbols (color, stroke, opacity), click Symbols and change the settings. For more information, see Change symbols.
- To change how the proportional symbols are applied to the data, adjust the bounding handles along the histogram. You can either drag the handle or click the number beside the handle and type a precise value. All values above the upper handle are drawn with the same largest symbol. Values below the lower handle are displayed with the same smallest symbol. The remaining values in between are drawn with a proportional sequence of sizes between the two bounds. Experiment with the position of the handles and use the histogram to see the distribution of the data to fine-tune the message of the map.
- To invert the symbol size order, click Invert.To adjust the size of the symbols, choose a minimum and maximum Size in pixels.
Note:
By default, older features are drawn with larger symbols and younger features are drawn with smaller symbols. Clicking Invert allows you to reverse this pattern.
- If you are mapping data associated with polygons, choose to adjust the size range automatically or specify the size range. For the automatic option, the symbols are optimized for the initial map zoom level and will automatically adjust so they look better across more zoom levels.
- To see details in the histogram more closely, click Zoom in.
- If you are mapping data associated with polygons, click Polygons to adjust the fill and stroke properties of the polygons.
- To draw locations with missing data on the map, check Draw features with no value. Uncheck it to hide the features.
- If you are mapping point symbols, you have the option to rotate symbols based on a second numeric field. For example, the color of the points could depict air temperature at weather stations, while the rotation of the points depicts humidity. The default symbol is round, which doesn't depict rotation very well. It is best to choose a different shape.
- To hide the size ramp in the legend, uncheck the Show in legend box.
- To change the transparency, move the Transparency slider to the left (less transparent) or the right (more transparent). To adjust the transparency of age per feature, click Attribute Values, choose an attribute field, optionally choose an attribute to divide by (for normalizing numeric data only), and set precise transparency values. You can only adjust per feature if you have date or numeric data associated with your locations. For example, if your layer contains urban areas, you could adjust the transparency of each location proportional to its size. If you want to hide the transparency ramp in the legend, uncheck the Show in legend box.
- To calculate and set the optimal visible range, click Suggest next to the Visible Range slider. You can also manually set the visible range.
- 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.
Color (Age) and Size and Color and Size (Age)
You can use these styles to show two attributes on your map using color and proportional symbols to see the age of features in your data. Age reflects the length of time (in seconds, minutes, hours, days, months, or years) from a start date or time to an end date or time. The Color (Age) and Size or Color and Size (Age) style can be used when you choose one date attribute and one numeric attribute, or two date attributes. For example, in a map showing approximate locations where migrants went missing, you can use color to show when migrants went missing based on the date the incident was reported, and use proportional symbols to show how many migrants were found dead. See an example.
Note:
This style is available for hosted feature layers, feature collections, and CSV layers.
One date and one numeric attribute
If you choose one date attribute and one numeric attribute, you can use color to show the age of features and use proportional symbols to represent the numeric attribute values. To do this, choose the date attribute as your first attribute and the numeric attribute as your second attribute, and then select the Color (Age) and Size style.
Alternatively, you can use proportional symbols to represent the age of features and use color to represent the numeric attributes by switching the order of the selected attributes and choosing the Color and Size (Age) style.
To style one date attribute and one numeric attribute to show age, do the following:
- Follow the first four steps in the Change style workflow.
- Choose the first attribute to show.
- Click Add attribute and choose the second attribute to show. For mapping styles that show the age of features, choose at least one attribute that contains date values. The other attribute can contain date values or numeric values.
You will see different options for showing age depending on the order of attributes you chose and whether you chose one date attribute and one numeric attribute, or two date attributes. To switch the order of the attributes, click the Switch Attributes button
. - Click any of the age styles offered and click Options.
- Apply the options for either of the following combinations: Age (Color) and Counts and Amounts (Size), or Counts and Amounts (Color) and Age (Size).
Two date attributes
If you choose two date attributes, you can decide whether you want to use color or proportional symbols to show the age of features based on one of the date attributes. A continuous timeline based on the other date attribute is shown using the other rendering option (color or size). You can even choose the same date attribute twice to show both age and a continuous timeline based on that same attribute.
Color (Age) and Size uses color to represent age based on the first date attribute, and uses proportional symbols to represent dates as a continuous timeline based on the second date attribute.
Color and Size (Age) does the reverse of Color (Age) and Size, using color for the continuous timeline and proportional symbols for the age of features. For example, in a map showing city code violations and compliance dates, you can use color to show complaint dates as a continuous timeline from older complaints to newer complaints, and use larger symbols to emphasize code violations that have gone uncorrected for a significant amount of time. See an example.
To style two date attributes to show age, do the following:
- Follow the first four steps in the change style workflow.
- Choose the first attribute to show.
- Click Add attribute and choose the second attribute to show. For mapping styles that show the age of features, choose at least one attribute that contains date values. The other attribute can contain date values or numeric values.
You will see different options for showing age depending on the order of attributes you chose and whether you chose one date attribute and one numeric attribute, or two date attributes. To switch the order of the attributes, click the Switch Attributes button
. - Click any of the age styles offered and click Options.
- Apply options for either of the following combinations: Age (Color) and Continuous Timeline (Size), or Continuous Timeline (Color) and Age (Size).
Types and Size (Age)
If your layer contains unique values (types) and date or time values, you can use color to show different categories, or types, of features based on the unique values, and proportional symbols to show the age of features. Age reflects the length of time (in seconds, minutes, hours, days, months, or years) from a start date or time to an end date or time. For example, in a map comparing Visa and Amex credit card payments, you can use a different color to represent each credit card company and different-sized symbols to show the length of time since payment. See an example.
Note:
This style is available for hosted feature layers, feature collections, and CSV layers.
To style two attributes using color to show different types and proportional symbols to show age, do the following:
- Follow the first four steps in the Change style workflow.
- Choose the first attribute to show. For this mapping style, choose an attribute that contains unique values.
- Click Add attribute and choose the second attribute to show. For this mapping style, choose an attribute that contains date values.
- Click the Types and Size (Age) style and click Options.
- Apply options to Types (Unique symbols) (first attribute) and Age (Size) (second attribute).