Subdiagonal
The subdiagonal of a square matrix is the set of elements directly under the elements comprising the diagonal. For example, in the following matrix, the diagonal elements are denoted d_i and the subdiagonals are denoted s_i,
![画像: [d_1 a_(12) a_(13) ... a_(1n); s_1 d_2 a_(23) ... a_(2n); a_(31) s_2 d_3 ... a_(3n); | ... ... ... ...; a_(n1) a_(n2) a_(n3) ... d_n].](/index.cgi/contrast/https://mathworld.wolfram.com/images/equations/Subdiagonal/NumberedEquation1.svg){kind=link}
See also
Diagonal, Jordan Block, Superdiagonal, Tridiagonal MatrixExplore with Wolfram|Alpha
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References
Faddeeva, V. N. Computational Methods of Linear Algebra. New York: Dover, p. 50, 1958.Referenced on Wolfram|Alpha
SubdiagonalCite this as:
Weisstein, Eric W. "Subdiagonal." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/Subdiagonal.html