ReplaceSubdiagonal
Returns a matrix with its subdiagonal replaced by a given vector.
Syntax
-
ReplaceSubdiagonal(A, v)
-
A
is a matrix -
v
is a vector
-
Description
If A
is an m×n
matrix and v
a vector of dimension m − 1
if m ≤ n
and n
if m > n
, then ReplaceSubdiagonal(A, v)
returns the matrix obtained from A
by replacing its subdiagonal with the components of v
(in order).
Examples
A ≔ ❨❨5, 1, 2, 3, 4❩, ❨4, 0, 2, 1, 7❩, ❨6, 3, 0, 4, 7❩, ❨4, 5, 2, 3, 9❩, ❨4, 0, 1, 2, 5❩❩
⎛5 1 2 3 4⎞ ⎜4 0 2 1 7⎟ ⎜6 3 0 4 7⎟ ⎜4 5 2 3 9⎟ ⎝4 0 1 2 5⎠
ReplaceSubdiagonal(A, ❨i, i, i, i❩)
⎛5 1 2 3 4⎞ ⎜i 0 2 1 7⎟ ⎜6 i 0 4 7⎟ ⎜4 5 i 3 9⎟ ⎝4 0 1 i 5⎠