An irregular matrix, or ragged matrix, is a
matrix
Matrix (: matrices or matrixes) or MATRIX may refer to:
Science and mathematics
* Matrix (mathematics), a rectangular array of numbers, symbols or expressions
* Matrix (logic), part of a formula in prenex normal form
* Matrix (biology), the m ...
that has a different number of elements in each row. Ragged matrices are not used in
linear algebra
Linear algebra is the branch of mathematics concerning linear equations such as
:a_1x_1+\cdots +a_nx_n=b,
linear maps such as
:(x_1, \ldots, x_n) \mapsto a_1x_1+\cdots +a_nx_n,
and their representations in vector spaces and through matrix (mathemat ...
, since standard matrix transformations cannot be performed on them, but they are useful in
computing
Computing is any goal-oriented activity requiring, benefiting from, or creating computer, computing machinery. It includes the study and experimentation of algorithmic processes, and the development of both computer hardware, hardware and softw ...
as
arrays which are called
jagged array
In computer science, a jagged array, also known as a ragged array or irregular array is an array data structure, array of arrays of which the member arrays can be of different lengths, producing rows of jagged edges when visualized as output. ...
s. Irregular matrices are typically stored using
Iliffe vector
In computer programming, an Iliffe vector, also known as a display, is a data structure used to implement multi-dimensional array data structure, arrays.
Data structure
An Iliffe vector for an ''n''-dimensional array (where ''n'' ≥ 2) ...
s.
For example, the following is an irregular matrix:
:
See also
*
Regular matrix (disambiguation)
*
Empty matrix
In mathematics, a matrix (: matrices) is a rectangular array or table of numbers, symbols, or expressions, with elements or entries arranged in rows and columns, which is used to represent a mathematical object or property of such an object. ...
*
Sparse matrix
In numerical analysis and scientific computing, a sparse matrix or sparse array is a matrix in which most of the elements are zero. There is no strict definition regarding the proportion of zero-value elements for a matrix to qualify as sparse ...
References
* Paul E. Black
Ragged matrix from
Dictionary of Algorithms and Data Structures, Paul E. Black, ed.,
NIST
The National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into physical s ...
, 2004.
Arrays
Matrices (mathematics)
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