Column chart symbols are used with maps to show the number of occurrences or proportions of categorical data associated to a single feature, using either a count or a summary statistic. Column chart symbols are created on a map using a string field and a location field containing coincident values.
Column chart symbols can answer questions about data, such as the following:
- How are categorical values distributed geographically?
- How is the data ranked?
Example
A GIS analyst working for a consortium of colleges wants to find which states have high-value colleges (colleges with a high ratio of earnings after graduation compared to tuition and fee costs). Part of her analysis includes comparing the number of public, private for-profit, and private nonprofit schools both within and between states. Creating a map with column chart symbols allows the analyst to make both comparisons simultaneously.
The analyst can tell from the map that the states with larger populations have more colleges overall. She decides to normalize the data by changing the symbols from Expanded to Stacked Percent. That way, she can compare the proportions of college types between states without being influenced by the total numbers of colleges in the state.
Create a map with column chart symbols
Note:
Column chart symbols can only be created with multipart datasets in which features are collocated. These datasets can be created using a one-to-many join, or by enabling location on a dataset. If location is enabled with addresses or coordinates, Repeat identical features must remain unselected.
Complete the following steps to create a map with column chart symbols:
- Create a multipart dataset by dong one of the following:
Create a join between two datasets. Generally, these datasets will include the features you want to display on the map and a boundary layer.
The join should be one-to-many, meaning each boundary feature contains more than one feature to map. In the example above, a join was created between a dataset with insurance data and state boundaries.
Enable location for the dataset.
If you enable location for points using addresses or coordinates, Repeat identical features must remain unselected. Enable location only when multiple data points appear in the exact same location. For example, a dataset containing monthly status updates for fire hydrants in a city could contain a new input each month for each fire hydrant. Enabling location without repeating identical features will aggregate the inputs for each hydrant.
If you enable location using geography, ensure that there are multiple features within each boundary. This method functions the same as a one-to-many join.
- Expand a dataset in the data pane so that the fields are visible.
- Select one of the following combinations of data:
- A location field and a string field
- A location field, a string field, and a number field or a rate/ratio field
If you created a join in step 1, the location field you select must be the field that corresponds to the boundaries.
Tip:
You can search for fields using the search bar in the data pane.
- Drag the field to the page to the Map drop zone.
Note:
You can also create a map by selecting a field and clicking the Map button above the data pane.
If the map was created using a location field, string field, and number or rate/ratio field, the map will be styled using pie chart symbols. If the map was created using a location field and a string field, the map will be styled using unique symbols.
- Expand the legend to display the Layer options pane.
- Browse to the Symbology tab
. - Change Symbol type to Columns.
Usage notes
To access the Layer options pane, click the arrow next to the layer name. You can do the following in the Layer options pane:
- Use the Legend tab
to view the unique values on the map and make selections based on the values. To change the color associated with a value, click the symbol and choose a color from the palette or provide a hexadecimal value. - Use the Symbology tab to do the following:
- Change the field and statistic displayed on the map or switch to a different type of map.
- Change the display between Stacked Count, Stacked Percent, and Expanded.
- Stacked Count—Each geographic feature is symbolized using a single bar with categories visualized as subgroups of the bar. The bar height is determined by the overall value of the Style by field and statistic, and the height of each category segment is determined by the statistic for the category.
- Stacked Percent—Each geographic feature is symbolized using a single bar with categories visualized as subgroups of the bar. The bar height is uniform for each geographical feature, and the height of each category segment represents the percentage of that category relative to the geographic feature.
- Expanded—Each category is represented by a separate bar. Bar heights are determined by the Style by field and statistic for each category.
- Use the Annotation tab
to configure the map pop-ups for the layer. - Use the Appearance tab
to do the following:- Symbols—Change the symbol style properties, such as symbol size and layer transparency.
- Layer effects—Enable bloom and drop shadow effects.
- Use the Attributes tab
to view details for features that are selected on the map.
Use the Card filter button 
to remove any unwanted data from the card. Filters can be applied to all string, number, rate/ratio, and date/time fields. A card filter does not affect other cards using the same dataset.
Use the Selection tools button 
to select features on the map using the single select, box select, and lasso tools; zoom to the selection; or invert the selection.
Use the Zoom tools button 
to zoom in or out on the map, zoom to a selection, set the default extent of the map, zoom to a layer, or lock navigation on the map.
Use the Visualization type button 
to switch directly between a map with column chart symbols and other visualizations, such as a summary table, stacked bar chart, chord diagram, or treemap.
Use the Sync extents button 
to link the extent of all maps on the page so they zoom and pan simultaneously.
Use the Maximize button 
to enlarge the card. Other cards on the page will be reduced to thumbnails. The card can be returned to its previous size using the Restore down button 
.
Use the Enable cross filters button 
to allow filters to be created on the card using selections on other cards. Cross filters can be removed using the Disable cross filters button 
.
Use the Flip card button 
to view the back of the card. The Card info tab 
includes a count of features and a text box for a description of the card.
Use the Card options button 
to access the following options:
- Appearance button —Change the background color, foreground color, border of the card, and map rotation, and add or remove the basemap layers and north arrow.
- Order button
—Move the card forward or move the card backward relative to other cards on the page. - Delete button
—Remove the card from the page. If you did not intend to delete the card, you can retrieve it using the Undo button 
.
Limitations
Column chart symbols show all unique categories associated with a single feature or location. If the features contain many unique categories or large differences between minimum and maximum counts, the column chart symbols may be difficult to interpret.
Resources
Use the following resources to learn more about maps: