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◆ Zgeqp3()
| Sub Zgeqp3 |
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M As |
Long, |
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N As |
Long, |
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A() As |
Complex, |
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Jpvt() As |
Long, |
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Tau() As |
Complex, |
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Info As |
Long |
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QR分解 (ピボット選択付き) (複素行列)
- 目的
- 本ルーチンは行列AのQR分解をピボット選択付きで計算する. 計算にはレベル3 BLASを用いる.
- 引数
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| [in] | M | 行列 A の行数. (M >= 0) (M = 0 の場合, 処理を行わずに戻る) |
| [in] | N | 行列 A の列数. (N >= 0) (N = 0 の場合, 処理を行わずに戻る) |
| [in,out] | A() | 配列 A(LA1 - 1, LA2 - 1) (LA1 >= M, LA2 >= N)
[in] M×N行列 A.
[out] 上三角部分にmin(M, N)×N上台形行列Rが入る. 対角下の要素は, 配列Tau()と合わせて, min(M, N)個の基本鏡映変換の積としてユニタリ行列Qを表す. |
| [in,out] | Jpvt() | 配列 Jpvt(LJpvt - 1) (LJpvt >= N)
[in] Jpvt(j-1) <> 0 の場合, Aの第j列はA*Pの前(先頭列)に入れ替えられる. Jpvt(j-1) = 0 の場合, Aの第j列はフリーな列である.
[out] Jpvt(j-1) = k の場合, A*Pの第j列は第k列であったことを示す. |
| [out] | Tau() | 配列 Tau(LTau - 1) (LTau >= min(M, N))
基本鏡映変換のスカラー因子. |
| [out] | Info | = 0: 正常終了.
= -1: パラメータ M の誤り. (M < 0)
= -2: パラメータ N の誤り. (N < 0)
= -3: パラメータ A() の誤り.
= -4: パラメータ Jpvt() の誤り.
= -5: パラメータ Tau() の誤り. |
- 出典
- LAPACK
- 使用例
- 行列Aの行列AのQR分解を求める. ただし,
( 0.20-0.11i -0.93-0.32i 0.81+0.37i )
A = ( -0.80-0.92i -0.29+0.86i 0.64+0.51i )
( 0.71+0.59i -0.15+0.19i 0.20+0.94i )
とする. Sub Ex_Zgeqp3()
Const M = 3, N = 3, K = N
Dim A(M - 1, N - 1) As Complex, Jpvt(N - 1) As Long, Tau(N - 1) As Complex
Dim Info As Long, I As Long
A(0, 0) = Cmplx(0.2, -0.11): A(0, 1) = Cmplx(-0.93, -0.32): A(0, 2) = Cmplx(0.81, 0.37)
A(1, 0) = Cmplx(-0.8, -0.92): A(1, 1) = Cmplx(-0.29, 0.86): A(1, 2) = Cmplx(0.64, 0.51)
A(2, 0) = Cmplx(0.71, 0.59): A(2, 1) = Cmplx(-0.15, 0.19): A(2, 2) = Cmplx(0.2, 0.94)
For I = 0 To N - 1
Jpvt(I) = 1
Next
Call Zgeqp3(M, N, A(), Jpvt(), Tau(), Info)
Debug.Print "R ="
Debug.Print "Jpvt =", Jpvt(0), Jpvt(1), Jpvt(2)
Debug.Print "Info =", Info
Call Zungqr(M, N, K, A(), Tau(), Info)
Debug.Print "Q ="
Debug.Print "Info =", Info
End Sub
Function Cmplx(R As Double, Optional I As Double=0) As Complex 複素数の作成
Function Cimag(A As Complex) As Double 複素数の虚数部
Function Creal(A As Complex) As Double 複素数の実数部
Sub Zgeqp3(M As Long, N As Long, A() As Complex, Jpvt() As Long, Tau() As Complex, Info As Long) QR分解 (ピボット選択付き) (複素行列)
Sub Zungqr(M As Long, N As Long, K As Long, A() As Complex, Tau() As Complex, Info As Long) QR分解の行列Qの生成 (複素行列)
- 実行結果
R =
-1.54618886297891 0 0.455571771900423 0.580588841049134
0.105614523497074 -0.57774313435356
1.14235325460067 0 -0.16000635361559 -0.558214300362838
1.30543219081149 0
Jpvt = 1 2 3
Info = 0
Q =
-0.129350304344243 7.11426673893335E-02 -0.726366393673366 -0.242754372725663
0.517401217376971 0.595011399983517 -0.157793930669391 0.252577062211036
-0.459193580422062 -0.381583397815516 -0.142116660471961 0.551879456556921
0.614237041991267 -0.119926029506194
5.77211185374505E-02 0.535006158572045
0.105825585638305 0.554588344523916
Info = 0
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