Interpolation

Interpolation defines how values are estimated between known samples—used for resampling and when computing aggregation boundaries.

• Linear Interpolation Values between two samples are placed on the straight line connecting them. Use for signals that change continuously (e.g., temperatures, flow). The example below shows the linear interpolation at t₁ and t₂, generating v'₀ and v'₂.

  

  Example of linear interpolation.
• Stairstep (Step-hold) Each value is held constant until the next sample arrives, producing a step-like profile. Use for setpoints, states, and other discrete changes. The example below shows stairstep interpolation at t₁ and t₂, generating v'₀ and v'₂.

  

  Example of stairstep interpolation.

Practical guidance

Use Stairstep interpolation for discrete/stateful signals like setpoints to avoid artificial ramps during resampling.

Use Linear interpolation for measurements coming from a continuous process. For example measuring (temperature, flow, distance etc.) or regulation.