NIST

upper triangular matrix

(data structure)

Definition: A matrix that is only defined at (i,j) when i ≤ j.

Generalization (I am a kind of ...)
matrix.

Specialization (... is a kind of me.)
strictly upper triangular matrix, .

See also lower triangular matrix, ragged matrix.

Note: For example

j
i 1776
-911
--88
---1

It may be more compactly represented in an array by storing entry (i,j) in location n(i-1) + j - i(i-1)/2 = (2n-i)(i-1)/2 + j one-based indexing.

Author: PEB

Implementation

(Fortran)
Go to the Dictionary of Algorithms and Data Structures home page.

If you have suggestions, corrections, or comments, please get in touch with Paul E. Black.

Entry modified Fri Dec 17 12:28:59 2004.
HTML page formatted Wed Oct 26 09:48:20 2005.

Cite this as:
Paul E. Black, "upper triangular matrix", from Dictionary of Algorithms and Data Structures, Paul E. Black, ed., NIST.
http://www.nist.gov/dads/HTML/upperTriangularMatrix.html

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