enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Time-scale calculus - Wikipedia

    en.wikipedia.org/wiki/Time-scale_calculus

    A time scale (or measure chain) is a closed subset of the real line. The common notation for a general time scale is T {\displaystyle \mathbb {T} } . The two most commonly encountered examples of time scales are the real numbers R {\displaystyle \mathbb {R} } and the discrete time scale h Z {\displaystyle h\mathbb {Z} } .

  3. Discrete time and continuous time - Wikipedia

    en.wikipedia.org/wiki/Discrete_time_and...

    A variable measured in discrete time can be plotted as a step function, in which each time period is given a region on the horizontal axis of the same length as every other time period, and the measured variable is plotted as a height that stays constant throughout the region of the time period. In this graphical technique, the graph appears as ...

  4. Time scale - Wikipedia

    en.wikipedia.org/wiki/Time_scale

    Time scale may refer to: Time standard, a specification of either the rate at which time passes, points in time, or both; A duration or quantity of time: Orders of magnitude (time) as a power of 10 in seconds; A specific unit of time; Geological time scale, a scale that divides up the history of Earth into scientifically meaningful periods

  5. Decomposition of time series - Wikipedia

    en.wikipedia.org/wiki/Decomposition_of_time_series

    This is an important technique for all types of time series analysis, especially for seasonal adjustment. [2] It seeks to construct, from an observed time series, a number of component series (that could be used to reconstruct the original by additions or multiplications) where each of these has a certain characteristic or type of behavior.

  6. Discrete-time Fourier transform - Wikipedia

    en.wikipedia.org/wiki/Discrete-time_Fourier...

    From uniformly spaced samples it produces a function of frequency that is a periodic summation of the continuous Fourier transform of the original continuous function. In simpler terms, when you take the DTFT of regularly-spaced samples of a continuous signal, you get repeating (and possibly overlapping) copies of the signal's frequency ...

  7. Indicator function - Wikipedia

    en.wikipedia.org/wiki/Indicator_function

    What appears to the modern reader as the representing function's logical inversion, i.e. the representing function is 0 when the function R is "true" or satisfied", plays a useful role in Kleene's definition of the logical functions OR, AND, and IMPLY, [2]: 228 the bounded-[2]: 228 and unbounded-[2]: 279 ff mu operators and the CASE function.

  8. Multiple-scale analysis - Wikipedia

    en.wikipedia.org/wiki/Multiple-scale_analysis

    In mathematics and physics, multiple-scale analysis (also called the method of multiple scales) comprises techniques used to construct uniformly valid approximations to the solutions of perturbation problems, both for small as well as large values of the independent variables. This is done by introducing fast-scale and slow-scale variables for ...

  9. Short-time Fourier transform - Wikipedia

    en.wikipedia.org/wiki/Short-time_Fourier_transform

    Simply, in the continuous-time case, the function to be transformed is multiplied by a window function which is nonzero for only a short period of time. The Fourier transform (a one-dimensional function) of the resulting signal is taken, then the window is slid along the time axis until the end resulting in a two-dimensional representation of the signal.