Measurements archetype

The new Measurements archetype logs scalar values together with their uncertainty. Use it for sensors that report a value and a variance: pressure, temperature, illuminance, relative humidity, range, and so on.

In a time series view each series is drawn as a line with a translucent band around it, one standard deviation (the square root of the variance) wide in each direction. Leave variances unset for values whose uncertainty is unknown.

Two new components come with it. Variance holds σ², in the units of the value squared, where 0 means a perfectly known value and draws no band. Unit holds a display-only unit such as "Pa" or "lux", shown in the legend and in tooltips.

Unlike Scalars, this archetype carries its own styling, so values and style are logged in one call:

rr.log(
    "pressure",
    rr.Measurements(values=pressures, variances=variances, units="Pa"),
)

Docs: ../reference/types/archetypes/measurements.md Example: ../reference/types/archetypes/measurements.md#example