(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 1 7 7 6 - 9 1 1 - - 8 8 - - - 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
If you have suggestions, corrections, or comments, please get in touch with Paul Black.
Entry modified 17 December 2004.
HTML page formatted Mon Feb 2 13:10:40 2015.
Cite this as:
Paul E. Black, "upper triangular matrix", in
Dictionary of Algorithms and Data Structures [online], Vreda Pieterse and Paul E. Black, eds. 17 December 2004. (accessed TODAY)
Available from: http://www.nist.gov/dads/HTML/upperTriangularMatrix.html