# Describe a Line Chart

## Details covered in the analysis

The length of the narrative and the level of detail the narrative contains depend on which Narrative length option is selected.

The line chart narrative includes:

• descriptive statistics stating total values and outliers across time.

• time-based variance analysis, i.e. comparison between time periods.

• trend detection, i.e. trend over the smallest unit of the selected time dimension, provided there are at least 5 data points available in the underlying data.

• correlation analysis over multiple measures, if multiple measures are selected.

The narrative wording depends on the selected aggregation types, referring, for example, to total, average, minimum or maximum values. For the Percentage, Rating and Ratio entity types, total values are omitted from the narrative as it does not make sense to sum up non-additive measures.

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## Data requirements

All NLG apps have the same data requirements for field names and formats. See Data requirements for details.

In addition, each app has specific data requirements:

If your data selection and configuration do not meet the requirements, the wizard disables the app and displays a warning:

### Dimensions and measures

This app can analyze line charts that depict:

• multiple measures, up to four time dimensions, and up to two non-time dimensions.

Minimum requirement: one measure and one time dimension.

### Important

For all time dimensions, make sure the Entity Type field in Step 2 is set to DateTime.

### Aggregation and entity types

Not all combinations of aggregation and entity types are supported for measures. The Describe a Line Chart app can analyze the following combinations:

### Note

Entity types and other data attributes are set in Step 2 of the wizard.

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## Narrative options

You can configure these narrative options in Step 3 of the NLG apps wizard:

OPTION

DESCRIPTION

LOCATION

Narrative length

Summary: produces a narrative of filtered facts in a more concise way than the Important things option.

Important things: produces a narrative of filtered facts based on Arria's ranking algorithm.

Tell me everything: produces a narrative that includes every fact extracted from your data by Arria's algorithms.

Default: Important things

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