MATLAB Function Reference |
Diagonal matrices and diagonals of a matrix
Syntax
Description
X = diag(v,k)
when v
is a vector of n
components, returns a square matrix X
of order n+abs(k)
, with the elements of v
on the k
th diagonal. k = 0
represents the main diagonal, k > 0
above the main diagonal, and k < 0
below the main diagonal.
X = diag(v)
puts v
on the main diagonal, same as above with k
=
0
.
v = diag(X,k)
for matrix X
, returns a column vector v
formed from the elements of the k
th diagonal of X
.
v = diag(X)
returns the main diagonal of X
, same as above with k
=
0
.
Examples
diag(diag(X))
is a diagonal matrix.
sum(diag(X))
is the trace of X
.
produces a tridiagonal matrix of order 2*m+1
.
See Also
deval | dialog |
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