← All chart types & primitives Trendline / annotation arrow
Visual primitive
Trendline / annotation arrow has_trendline
A fitted line or annotation overlay calling out the rate of change.
Trendlines are the strongest narrative tool in correlation/time-series charts. A scatter with a fitted line says "here is the slope". A bar chart with a CAGR arrow says "here is the growth rate". The annotation can be a fitted curve, a simple arrow with a number, or both.
When critical
When the rate / slope IS the takeaway. Common in growth-story bar charts and editorial scatters.
When optional
When the chart is purely descriptive (showing levels, not change).
Failures when missing
- hero-with-no-takeaway
- reader has to infer the slope themselves
Failures when present (badly)
- fitted line on data that is not actually linear (misleading)
- CAGR arrow with no R² / fit quality
Critical for families
- correlation
- time-series
Aspose property bindings
Trendlines.typeTrendlines.equationTrendlines.RSquared