@sym: M = diag (v) ¶@sym: M = diag (v, k) ¶@sym: M = diag (v, n, m) ¶@sym: v = diag (A) ¶@sym: v = diag (A, k) ¶Make diagonal matrix or extract diagonal of symbolic matrix.
Example:
A = sym([1 2 3; 4 5 6; 7 8 9])
⇒ A = (sym 3×3 matrix)
⎡1 2 3⎤
⎢ ⎥
⎢4 5 6⎥
⎢ ⎥
⎣7 8 9⎦
v = diag(A)
⇒ v = (sym 3×1 matrix)
⎡1⎤
⎢ ⎥
⎢5⎥
⎢ ⎥
⎣9⎦
Make it back into a matrix:
diag(v)
⇒ (sym 3×3 matrix)
⎡1 0 0⎤
⎢ ⎥
⎢0 5 0⎥
⎢ ⎥
⎣0 0 9⎦
See also: @@sym/repmat.
Package: symbolic