Hetkeväärtusi

Hetkeväärtusi is an Estonian-language term used to refer to instantaneous values—the value of a quantity at a specific moment in time. The singular form is hetkeväärtus and the plural is hetkeväärtusi. The word hetke means “moment” and väärtus means “value.” In mathematics, physics, and engineering, hetkeväärtusi describe the current state of a time-dependent quantity, distinct from averages, totals, or integrals over an interval.

In continuous-time models, the hetkeväärtus of a function f at time t0 is f(t0). In digital signal processing and data acquisition, hetkeväärtusi are approximated by samples f(t_k) taken at sampling times t_k; the set of samples over an interval constitutes a sequence of hetkeväärtusi. The concept is central to understanding how signals and quantities are observed at precise moments rather than across a span of time.

Computation and measurement: If f is known analytically, the instantaneous value at t0 is obtained by direct evaluation. If only discrete data are available, estimation through interpolation or filtering provides an estimated hetkeväärtus. Potential sources of error include timing jitter, sampling rate limitations, and quantization.

Examples: In electronics, the instantaneous voltage v(t) at time t0 is a hetkeväärtus of the signal v. In mechanics, the instantaneous velocity is the hetkeväärtus of the position function at time t. In economics, an instrument might report hetkeväärtusi for a price or rate at a particular moment.

See also: instantaneous value, sampling, time series, interpolation.