Ti̍t-kau hâng-lia̍t

Ti̍t-kau hâng-lia̍t (Hàn-jī: 直交行列, Eng-gí: orthogonal matrix) sī chi̍t khoán si̍t sù-hong hâng-lia̍t, i ê choán-tì téng-î i ê ge̍k:

$A^{\mathrm {T} }=A^{-1}$,

khiā-sǹg-kóng

$A^{\mathrm {T} }A^{-1}=A^{-1}A^{\mathrm {T} }=I$,

kî-tiong $I$ sī tan-ūi hâng-lia̍t.

Lē

Chia ê lē lóng sī ti̍t-kau hâng-lia̍t:

• ${\begin{pmatrix}1&0\\0&1\\\end{pmatrix}}$    (tông-téng piàn-ōaⁿ)
• ${\begin{pmatrix}\cos \theta &-\sin \theta \\\sin \theta &\cos \theta \\\end{pmatrix}}$   (tńg-se̍h $\theta$)
• ${\begin{pmatrix}\cos 16.26^{\circ }&-\sin 16.26^{\circ }\\\sin 16.26^{\circ }&\cos 16.26^{\circ }\\\end{pmatrix}}\approx \left({\begin{array}{rr}0.96&-0.28\\0.28&0.96\\\end{array}}\right)$  (tńg-se̍h $16.26^{\circ }$)
• ${\begin{pmatrix}1&0\\0&-1\\\end{pmatrix}}$    (thàu-kòex-te̍k ê kiàⁿ-siōng)
• ${\begin{pmatrix}0&0&0&1\\0&0&1&0\\1&0&0&0\\0&1&0&0\end{pmatrix}}$    (thè-ōaⁿ chō-piau-te̍k)