This page describes the layout of matrices in the memory of computers. See linear representation for group representations by matrices.

A matrix representation is a method used by a computer language to store matrices of of more than one dimension in memory.

Fortran and C use different schemes. Fortran uses "Column Major", in which all the elements for a given column are stored contiguously in memory. C uses "Row Major", which stores all the elements for a given row contiguously in memory.

LAPACK defines various matrix representations in memory. There is also sparse matrix represention and Morton-order matrix represention .

According to the documentation, in LAPACK the unitary matrix representation is optimized. See [1].

External links

• http://developer.r-project.org/Sparse.html a description of sparse matrices in R.

R. LEHOUCQ, The computation of elementary unitary matrices, Computer Science Dept. Technical Report CS-94-233, University of Tennessee, Knoxville, 1994. (LAPACK Working Note 72).