“vector”的概念、定义、翻译、参考文献-科学参考

vector

Physics

A quantity in which both the magnitude and the direction must be stated (compare scalar quantity). Force, velocity, and field strength are examples of vector quantities. Note that distance and speed are scalar quantities, whereas displacement and velocity are vector quantities. Vector quantities must be treated by vector algebra; for example, the resultant of two vectors may be found by a parallelogram of vectors. A (three-dimensional) vector V may be written in terms of components V₁, V₂, and V₃ along the x, y, and z axes (say) as V₁i+V₂j+V₃k where i, j, and k are unit vectors (i.e. vectors of unit length) along the x, y, and z axes. See also triangle of vectors.

Mathematics

A mathematical object, possibly modelling a physical phenomenon, which has magnitude and direction. Examples from applied mathematics include force, velocity, and gravitational field (see gravity), but vectors are also used in pure mathematics, particularly in geometry.

A vector may be considered as the position vector $\vec{O P}$ of a point P from an origin O or as a translation vector, a movement of space. In this way the zero vector may considered as the position vector of the origin or as no translation. The distinction between a vector and a coordinate vector may in some contexts be important, especially if more than one coordinate system is being used; in this case the same vector may have different coordinates in the two systems.

With a given coordinate system, a vector can be identified with an ordered pair (x,y) or ordered triple (x,y,z), whether considered as a position vector or a translation vector. This definition can easily be generalized to other dimensions. Addition and scalar multiplication may be defined componentwise. Other operations are important (see scalar product, vector product).

Statistics

A matrix with only one column (a column vector) or only one row (a row vector).

Chemical Engineering

1. A representation of a quantity having both magnitude and direction. Force, velocity, and acceleration are all vectors.

2. A carrier of genetic material such as a bacteria carrying recombinant DNA fragments for another microbial species.

Computer

A one-dimensional array. In computing, vectors are widely used since the memory is essentially a vector of words. The notation for vectors is determined by the programming language. In this dictionary a bold italic lower-case letter, e.g. v, is used to denote a vector in its entirety, and the corresponding plain italic lower-case letter indexed by a subscript, e.g. v_i, is used to denote an element of the vector.
A vector may also be used to express a deficient matrix, in which case it is necessary to distinguish between a row vector and a column vector.

Biology

1. An animal, usually an insect, that passively transmits disease-causing microorganisms from one animal or plant to another or from an animal to a human. Compare carrier.
2. (cloning vector) A vehicle used in gene cloning to insert a foreign DNA fragment into the genome of a host cell. For bacterial hosts several different types of vector are used: bacteriophages, artificial chromosomes, plasmids, and their hybrid derivatives, cosmids. The foreign DNA is spliced into the vector using specific restriction enzymes and DNA ligases to cleave the vector DNA and join the foreign DNA to the two ends created (insertional vectors). In some phage vectors, part of the viral genome is enzymically removed and replaced with the foreign DNA (replacement vectors). Retroviruses can be effective vectors for introducing recombinant DNA into mammalian cells. In plants, derivatives of the tumour-inducing (Ti) plasmid of the crown gall bacterium, Agrobacterium tumefaciens, are used as vectors. See also expression vector.

Geography

In geographic information systems (GIS), vector data represent features as discrete points, lines, and polygons. In computer graphics, vectorization refers to the process of converting raster graphics into vector graphics. Vectorization is not well defined, meaning there is not a single correct method. Many different algorithms exist, and each gives different results, as vector representations are more abstract than pixels (K.-T. Chang 2014).

单词	vector
释义	vector Physics A quantity in which both the magnitude and the direction must be stated (compare scalar quantity). Force, velocity, and field strength are examples of vector quantities. Note that distance and speed are scalar quantities, whereas displacement and velocity are vector quantities. Vector quantities must be treated by vector algebra; for example, the resultant of two vectors may be found by a parallelogram of vectors. A (three-dimensional) vector V may be written in terms of components V₁, V₂, and V₃ along the x, y, and z axes (say) as V₁i+V₂j+V₃k where i, j, and k are unit vectors (i.e. vectors of unit length) along the x, y, and z axes. See also triangle of vectors. Mathematics A mathematical object, possibly modelling a physical phenomenon, which has magnitude and direction. Examples from applied mathematics include force, velocity, and gravitational field (see gravity), but vectors are also used in pure mathematics, particularly in geometry. A vector may be considered as the position vector $\vec{O P}$ of a point P from an origin O or as a translation vector, a movement of space. In this way the zero vector may considered as the position vector of the origin or as no translation. The distinction between a vector and a coordinate vector may in some contexts be important, especially if more than one coordinate system is being used; in this case the same vector may have different coordinates in the two systems. With a given coordinate system, a vector can be identified with an ordered pair (x,y) or ordered triple (x,y,z), whether considered as a position vector or a translation vector. This definition can easily be generalized to other dimensions. Addition and scalar multiplication may be defined componentwise. Other operations are important (see scalar product, vector product). Statistics A matrix with only one column (a column vector) or only one row (a row vector). Chemical Engineering 1. A representation of a quantity having both magnitude and direction. Force, velocity, and acceleration are all vectors. 2. A carrier of genetic material such as a bacteria carrying recombinant DNA fragments for another microbial species. Computer A one-dimensional array. In computing, vectors are widely used since the memory is essentially a vector of words. The notation for vectors is determined by the programming language. In this dictionary a bold italic lower-case letter, e.g. v, is used to denote a vector in its entirety, and the corresponding plain italic lower-case letter indexed by a subscript, e.g. v_i, is used to denote an element of the vector. A vector may also be used to express a deficient matrix, in which case it is necessary to distinguish between a row vector and a column vector. Biology 1. An animal, usually an insect, that passively transmits disease-causing microorganisms from one animal or plant to another or from an animal to a human. Compare carrier. 2. (cloning vector) A vehicle used in gene cloning to insert a foreign DNA fragment into the genome of a host cell. For bacterial hosts several different types of vector are used: bacteriophages, artificial chromosomes, plasmids, and their hybrid derivatives, cosmids. The foreign DNA is spliced into the vector using specific restriction enzymes and DNA ligases to cleave the vector DNA and join the foreign DNA to the two ends created (insertional vectors). In some phage vectors, part of the viral genome is enzymically removed and replaced with the foreign DNA (replacement vectors). Retroviruses can be effective vectors for introducing recombinant DNA into mammalian cells. In plants, derivatives of the tumour-inducing (Ti) plasmid of the crown gall bacterium, Agrobacterium tumefaciens, are used as vectors. See also expression vector. Geography In geographic information systems (GIS), vector data represent features as discrete points, lines, and polygons. In computer graphics, vectorization refers to the process of converting raster graphics into vector graphics. Vectorization is not well defined, meaning there is not a single correct method. Many different algorithms exist, and each gives different results, as vector representations are more abstract than pixels (K.-T. Chang 2014).
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