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  2. Frequency (statistics) - Wikipedia

    en.wikipedia.org/wiki/Frequency_(statistics)

    A frequency distribution shows a summarized grouping of data divided into mutually exclusive classes and the number of occurrences in a class. It is a way of showing unorganized data notably to show results of an election, income of people for a certain region, sales of a product within a certain period, student loan amounts of graduates, etc.

  3. Intensity-duration-frequency curve - Wikipedia

    en.wikipedia.org/wiki/Intensity-duration...

    An intensity-duration-frequency curve (IDF curve) is a mathematical function that relates the intensity of an event (e.g. rainfall) with its duration and frequency of occurrence. [1] Frequency is the inverse of the probability of occurrence. These curves are commonly used in hydrology for flood forecasting and civil engineering for urban ...

  4. Time–frequency representation - Wikipedia

    en.wikipedia.org/wiki/Time–frequency...

    A time–frequency representation (TFR) is a view of a signal (taken to be a function of time) represented over both time and frequency. [1] Time–frequency analysis means analysis into the time–frequency domain provided by a TFR. This is achieved by using a formulation often called "Time–Frequency Distribution", abbreviated as TFD.

  5. Wigner distribution function - Wikipedia

    en.wikipedia.org/wiki/Wigner_distribution_function

    When the input signal is a delta function, since it is only non-zero at t=0 and contains infinite frequency components, its time-frequency distribution should be a vertical line across the origin. This means that the time frequency distribution of the delta function should also be a delta function. By WDF

  6. Cumulative frequency analysis - Wikipedia

    en.wikipedia.org/wiki/Cumulative_frequency_analysis

    Frequency analysis [2] is the analysis of how often, or how frequently, an observed phenomenon occurs in a certain range. Frequency analysis applies to a record of length N of observed data X 1, X 2, X 3. . . X N on a variable phenomenon X. The record may be time-dependent (e.g. rainfall measured in one spot) or space-dependent (e.g. crop ...

  7. Bilinear time–frequency distribution - Wikipedia

    en.wikipedia.org/wiki/Bilinear_time–frequency...

    The relationship between the Wigner distribution function, the auto-correlation function and the ambiguity function can then be illustrated by the following figure. By comparing the definition of bilinear (or quadratic) time–frequency distributions with that of the Wigner distribution function, it is easily found that the latter is a special ...

  8. Choi–Williams distribution function - Wikipedia

    en.wikipedia.org/wiki/Choi–Williams...

    Choi–Williams distribution function is one of the members of Cohen's class distribution function. [1] It was first proposed by Hyung-Ill Choi and William J. Williams in 1989. This distribution function adopts exponential kernel to suppress the cross-term.

  9. Spectral leakage - Wikipedia

    en.wikipedia.org/wiki/Spectral_leakage

    The Fourier transform of a function of time, s(t), is a complex-valued function of frequency, S(f), often referred to as a frequency spectrum.Any linear time-invariant operation on s(t) produces a new spectrum of the form H(f)•S(f), which changes the relative magnitudes and/or angles of the non-zero values of S(f).