Line graphs show information as a series of data points that are connected by straight line segments. Categories are shown along the x-axis, and statistics are shown along the y-axis. Unlike time series graphs, which only use date and time along the category axis, line graphs allow you to use string fields along the category axis.
Line graphs can answer questions about your data, such as: How are numeric values distributed or summarized by category?
An environmental organization is tracking the drought conditions in Southern California and wants to compare precipitation levels across the region to determine which cities are most vulnerable. The organization uses a line graph to show the total precipitation for each city.
Create a line graph
To create a line graph, complete the following steps:
- Select one of the following data options:
- One or two string fields
- One or two string fields plus a number or rate/ratio field
If you do not select a number or rate/ratio field, your data will be aggregated and a count will be displayed.
You can search for fields using the search bar in the data pane.
- Create the line graph using the following steps:
- Drag the selected fields to a new card.
- Hover over the Chart drop zone.
- Drop the selected fields on Line Graph.
Drag a matching string field from a second dataset onto your line graph to create a combo chart.
You can also create charts using the Chart menu above the data pane or the Visualization type button on an existing card. For the Chart menu, only charts that are compatible with your data selection will be enabled. For the Visualization type menu, only compatible visualizations (including maps, charts, or tables) will be displayed.
The Layer options button opens the Layer options pane. You can use the Layer options pane to view the legend, change the chart options, and update the chart style.
The Legend tab is used to view the symbols on the chart. The pop out legend button displays the legend as a separate card on your page. You can use the legend to make selections on the chart.
To change the color or pattern associated with a value, click the symbol and choose a color from the palette, enter a hex value, or select a pattern. Changing the symbol from the Legend tab is only available for unique symbols.
The Symbology tab is used to apply the Smooth line parameter and turn labels on or off. A smooth line is best in situations when you are displaying trends in your data without sudden changes, rather than when you want to see specific values. For example, showing trends in monthly temperature using a smooth line is an effective way to analyze seasonality.
Labels display the number values associated with the chart. The following configurations are available for labels:
- Decimal places — You can choose a number of decimal places from zero to five, or choose Default or Auto for the labels. Default will abbreviate large numbers, while Auto will choose an appropriate precision.
- Label alignment — Three alignment options are available for line graphs: Horizontal, outside,Vertical, outside, and Angled.
- Context label — Characters, such as a symbol or unit, can be added to the label. The context label can be placed to the left (default) or right of the value.
The Appearance tab is used to change the symbol color (single symbol only) and change the pattern and thickness of the line.
The trends for the line graph can be symbolized as a count of features over time or as a number or rate/ratio field. If a field is used, the values in the trend line can be calculated as the sum, minimum, maximum, average, percentile, or median of values from the field for each point in time.
Use the Chart statistics button to display the mean, median, upper quartile, lower quartile, or a custom value.
Use the Sort button to sort the categorical data either ascending or descending by the numeric variable, or alphabetically.
Use the Flip card button to view the back of the card. The Card info tab provides information about the data on the card, the Export image tab allows users to export an image of the card, and the Export data tab allows users to export the data from the card.
When you create a line graph, a result dataset with the string and number fields used to create the chart will be added to the data pane. The result dataset can be used to find answers with nonspatial analysis using the Action button .