Affine Arithmetic - Definition

Definition

In affine arithmetic, each input or computed quantity x is represented by a formula where are known floating-point numbers, and are symbolic variables whose values are only known to lie in the range .

Thus, for example, a quantity X which is known to lie in the range can be represented by the affine form, for some k. Conversely, the form implies that the corresponding quantity X lies in the range .

The sharing of a symbol among two affine forms, implies that the corresponding quantities X, Y are partially dependent, in the sense that their joint range is smaller than the Cartesian product of their separate ranges. For example, if and, then the individual ranges of X and Y are and, but the joint range of the pair (X,Y) is the hexagon with corners (2,27), (6,27), (18,19), (18,13), (14,13), (2,21) — which is a proper subset of the rectangle ×.

Read more about this topic:  Affine Arithmetic

Famous quotes containing the word definition:

    The man who knows governments most completely is he who troubles himself least about a definition which shall give their essence. Enjoying an intimate acquaintance with all their particularities in turn, he would naturally regard an abstract conception in which these were unified as a thing more misleading than enlightening.
    William James (1842–1910)

    I’m beginning to think that the proper definition of “Man” is “an animal that writes letters.”
    Lewis Carroll [Charles Lutwidge Dodgson] (1832–1898)

    ... if, as women, we accept a philosophy of history that asserts that women are by definition assimilated into the male universal, that we can understand our past through a male lens—if we are unaware that women even have a history—we live our lives similarly unanchored, drifting in response to a veering wind of myth and bias.
    Adrienne Rich (b. 1929)