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  2. Slowly changing dimension - Wikipedia

    en.wikipedia.org/wiki/Slowly_changing_dimension

    In data management and data warehousing, a slowly changing dimension (SCD) is a dimension that stores data which, while generally stable, may change over time, often in an unpredictable manner. [1] This contrasts with a rapidly changing dimension , such as transactional parameters like customer ID, product ID, quantity, and price, which undergo ...

  3. Dimension (data warehouse) - Wikipedia

    en.wikipedia.org/wiki/Dimension_(data_warehouse)

    The dimension is a data set composed of individual, non-overlapping data elements. The primary functions of dimensions are threefold: to provide filtering, grouping and labelling. These functions are often described as "slice and dice". A common data warehouse example involves sales as the measure, with customer and product as dimensions.

  4. Dimensionality reduction - Wikipedia

    en.wikipedia.org/wiki/Dimensionality_reduction

    Dimensionality reduction, or dimension reduction, is the transformation of data from a high-dimensional space into a low-dimensional space so that the low-dimensional representation retains some meaningful properties of the original data, ideally close to its intrinsic dimension.

  5. List of physical quantities - Wikipedia

    en.wikipedia.org/wiki/List_of_physical_quantities

    Dimension Comments Absement: A: Measure of sustained displacement: the first integral with respect to time of displacement m⋅s L T: vector Acceleration: a →: Rate of change of velocity per unit time: the second time derivative of position m/s 2: L T −2: vector Angular acceleration: ω a: Change in angular velocity per unit time rad/s 2: T ...

  6. Dimensional analysis - Wikipedia

    en.wikipedia.org/wiki/Dimensional_analysis

    For example, one might choose force, length and mass as the base dimensions (as some have done), with associated dimensions F, L, M; this corresponds to a different basis, and one may convert between these representations by a change of basis. The choice of the base set of dimensions is thus a convention, with the benefit of increased utility ...

  7. Fractal dimension - Wikipedia

    en.wikipedia.org/wiki/Fractal_dimension

    The theoretical fractal dimension for this fractal is 5/3 ≈ 1.67; its empirical fractal dimension from box counting analysis is ±1% [8] using fractal analysis software. A fractal dimension is an index for characterizing fractal patterns or sets by quantifying their complexity as a ratio of the change in detail to the change in scale.

  8. Change of basis - Wikipedia

    en.wikipedia.org/wiki/Change_of_basis

    A change of basis is sometimes called a change of coordinates, although it excludes many coordinate transformations. For applications in physics and specially in mechanics, a change of basis often involves the transformation of an orthonormal basis, understood as a rotation in physical space, thus excluding translations. This article deals ...

  9. Curse of dimensionality - Wikipedia

    en.wikipedia.org/wiki/Curse_of_dimensionality

    There is an exponential increase in volume associated with adding extra dimensions to a mathematical space.For example, 10 2 = 100 evenly spaced sample points suffice to sample a unit interval (try to visualize a "1-dimensional" cube) with no more than 10 −2 = 0.01 distance between points; an equivalent sampling of a 10-dimensional unit hypercube with a lattice that has a spacing of 10 −2 ...