An irregular matrix, or ragged matrix, can be described as a matrix

Matrix (mathematics)

In mathematics, a matrix is a rectangular array of numbers, symbols, or expressions. The individual items in a matrix are called its elements or entries. An example of a matrix with six elements isMatrices of the same size can be added or subtracted element by element...

 that has a different number of elements in each row. Ragged matrices are not used in linear algebra

Linear algebra

Linear algebra is a branch of mathematics that studies vector spaces, also called linear spaces, along with linear functions that input one vector and output another. Such functions are called linear maps and can be represented by matrices if a basis is given. Thus matrix theory is often...

, since standard matrix transformations cannot be performed on them, but they are useful as arrays in computing

Computing

Computing is usually defined as the activity of using and improving computer hardware and software. It is the computer-specific part of information technology...

. Irregular matrices are typically stored using Iliffe vector

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 consists of a vector of pointers to an -dimensional array...

s.

For example, the following is an irregular matrix:

See also

• Matrix(mathematics)
• Regular matrix
  Regular matrix
  Regular matrix may refer to:* regular stochastic matrix, a stochastic matrix such that all the entries of some power of the matrix are positive.* invertible matrix ....
  
  
• Sparse matrix
  Sparse matrix
  In the subfield of numerical analysis, a sparse matrix is a matrix populated primarily with zeros . The term itself was coined by Harry M. Markowitz....
  
  
• Array data structure