> For the complete documentation index, see [llms.txt](https://docs.tryterra.co/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.tryterra.co/faq/help-topics/data-api-sdk/data-model-fields-and-units/no-smoothing-sample-array-length-mismatch.md).

# Does Terra smooth samples, and why do array lengths differ?

Terra applies **no smoothing or post-processing** to sample data; values are piped through as the provider supplies them, so any smoothing you see is applied at the device or provider level.

Sample arrays (heart rate, position, elevation, distance) can have different lengths because null readings from the device are filtered out rather than passed through as empty samples.

**Align samples by timestamp rather than by index.**