Noun

(en-noun)

Specter, apparition.

A range; a continuous, infinite, one-dimensional set, possibly bounded by extremes.

* {{quote-news, year=2012, date=November 7, author=Matt Bai, title=Winning a Second Term, Obama Will Confront Familiar Headwinds, work=New York Times citation

, passage=As Mr. Obama prepared to take the oath, his approval rating touched a remarkable 70 percent in some polling — a reflection of good will across the political spectrum .}}

Specifically, a range of colours representing light (electromagnetic radiation) of contiguous frequencies; hence electromagnetic spectrum, visible spectrum, ultraviolet spectrum, etc.

* 2010 October 30, Jim Giles, Jammed!'', in '' ,

Current 3G technologies can send roughly 1 bit of data - a one or a zero - per second over each 1 Hz of spectrum that the operator owns.

(chemistry) The pattern of absorption or emission of radiation produced by a substance when subjected to energy (radiation, heat, electricity, etc.).

(mathematics, linear algebra) The set of eigenvalues of a matrix.

(mathematics, functional analysis) Of a bounded linear operator A'', the set of scalar values ? such that the operator ''A—?I'', where ''I denotes the identity operator, does not have a bounded inverse; intended as a generalisation of the linear algebra sense.

Noun

(en noun)

(mathematics, physics) A variable kept constant during an experiment, calculation or similar.

(programming) An input variable of a procedure definition, that gets an actual value (argument) at execution time (formal parameter) .

Roughly, a tuple of arguments could be thought of as a vector, whereas a tuple of parameters''' could be thought of as a covector (i.e., linear functional). When a function is called, a '''parameter tuple becomes "bound" to an argument tuple, allowing the function instance itself to be computed to yield a return value. This would be roughly analogous to applying a covector to a vector (by taking their dot product (or, rather, matrix-product of row vector and column vector)) to obtain a scalar.

(programming) An actual value given to such a formal parameter (argument or actual parameter) .

A characteristic or feature that distinguishes something from others.

(geometry) In the ellipse and hyperbola, a third proportional to any diameter and its conjugate, or in the parabola, to any abscissa and the corresponding ordinate.

The parameter of the principal axis of a conic section is called the latus rectum.

(crystallography) The ratio of the three crystallographic axes which determines the position of any plane.

(crystallography) The fundamental axial ratio for a given species.