An irregular matrix, or ragged matrix, is a
matrix
Matrix most commonly refers to:
* ''The Matrix'' (franchise), an American media franchise
** ''The Matrix'', a 1999 science-fiction action film
** "The Matrix", a fictional setting, a virtual reality environment, within ''The Matrix'' (franchis ...
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 matrices ...
, since standard matrix transformations cannot be performed on them, but they are useful as
array
An array is a systematic arrangement of similar objects, usually in rows and columns.
Things called an array include:
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Music
* In twelve-tone and serial composition, the presentation of simultaneous twelve-tone sets such that the ...
s in
computing
Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes, and development of both hardware and software. Computing has scientific, ...
. 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 arrays. An Iliffe vector for an ''n''-dimensional array (where ''n'' ≥ 2) consists of a vector (or 1-dimension ...
s.
For example, the following is an irregular matrix:
:
See also
*
Regular matrix (disambiguation) Regular matrix may refer to: Mathematics
* Regular stochastic matrix, a stochastic matrix such that all the entries of some power of the matrix are positive
* The opposite of irregular matrix, a matrix with a different number of entries in each ro ...
*
Empty matrix
*
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 b ...
*
Jagged array
In computer science, a jagged array, also known as a ragged array, irregular array is an array of arrays of which the member arrays can be of different lengths, producing rows of jagged edges when visualized as output. In contrast, two-dimensio ...
References
* Paul E. Black
Ragged matrix from
Dictionary of Algorithms and Data Structures
The NIST ''Dictionary of Algorithms and Data Structures'' is a reference work maintained by the U.S. National Institute of Standards and Technology. It defines a large number of terms relating to algorithms and data structures. For algorithms and ...
, Paul E. Black, ed.,
NIST, 2004.
{{Matrix classes
Arrays
Matrices