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 Legend button opens the Layer options pane. The Layer options pane contains the following functions:
- 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 when a subgroup is applied. To change the color associated with a value, click the symbol and choose a color from the palette or enter a hex value.
- The Options tab is used to apply the Smooth line parameter. 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.
- The Style tab is used to change the symbol color (single symbol only), change the pattern and thickness of the line, or turn labels on or off. Labels display the number values associated with the chart and can be configured based on the position, orientation, and number of 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.
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.
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 .