zgesv.f.html
来自「famous linear algebra library (LAPACK) p」· HTML 代码 · 共 132 行
HTML
132 行
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>zgesv.f</title>
<meta name="generator" content="emacs 21.3.1; htmlfontify 0.20">
<style type="text/css"><!--
body { background: rgb(255, 255, 255); color: rgb(0, 0, 0); font-style: normal; font-weight: 500; font-stretch: normal; font-family: adobe-courier; font-size: 11pt; text-decoration: none; }
span.default { background: rgb(255, 255, 255); color: rgb(0, 0, 0); font-style: normal; font-weight: 500; font-stretch: normal; font-family: adobe-courier; font-size: 11pt; text-decoration: none; }
span.default a { background: rgb(255, 255, 255); color: rgb(0, 0, 0); font-style: normal; font-weight: 500; font-stretch: normal; font-family: adobe-courier; font-size: 11pt; text-decoration: underline; }
span.string { color: rgb(188, 143, 143); background: rgb(255, 255, 255); font-style: normal; font-weight: 500; font-stretch: normal; font-family: adobe-courier; font-size: 11pt; text-decoration: none; }
span.string a { color: rgb(188, 143, 143); background: rgb(255, 255, 255); font-style: normal; font-weight: 500; font-stretch: normal; font-family: adobe-courier; font-size: 11pt; text-decoration: underline; }
span.comment { color: rgb(178, 34, 34); background: rgb(255, 255, 255); font-style: normal; font-weight: 500; font-stretch: normal; font-family: adobe-courier; font-size: 11pt; text-decoration: none; }
span.comment a { color: rgb(178, 34, 34); background: rgb(255, 255, 255); font-style: normal; font-weight: 500; font-stretch: normal; font-family: adobe-courier; font-size: 11pt; text-decoration: underline; }
--></style>
</head>
<body>
<pre>
SUBROUTINE <a name="ZGESV.1"></a><a href="zgesv.f.html#ZGESV.1">ZGESV</a>( N, NRHS, A, LDA, IPIV, B, LDB, INFO )
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> -- LAPACK driver routine (version 3.1) --
</span><span class="comment">*</span><span class="comment"> Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd..
</span><span class="comment">*</span><span class="comment"> November 2006
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> .. Scalar Arguments ..
</span> INTEGER INFO, LDA, LDB, N, NRHS
<span class="comment">*</span><span class="comment"> ..
</span><span class="comment">*</span><span class="comment"> .. Array Arguments ..
</span> INTEGER IPIV( * )
COMPLEX*16 A( LDA, * ), B( LDB, * )
<span class="comment">*</span><span class="comment"> ..
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> Purpose
</span><span class="comment">*</span><span class="comment"> =======
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> <a name="ZGESV.18"></a><a href="zgesv.f.html#ZGESV.1">ZGESV</a> computes the solution to a complex system of linear equations
</span><span class="comment">*</span><span class="comment"> A * X = B,
</span><span class="comment">*</span><span class="comment"> where A is an N-by-N matrix and X and B are N-by-NRHS matrices.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> The LU decomposition with partial pivoting and row interchanges is
</span><span class="comment">*</span><span class="comment"> used to factor A as
</span><span class="comment">*</span><span class="comment"> A = P * L * U,
</span><span class="comment">*</span><span class="comment"> where P is a permutation matrix, L is unit lower triangular, and U is
</span><span class="comment">*</span><span class="comment"> upper triangular. The factored form of A is then used to solve the
</span><span class="comment">*</span><span class="comment"> system of equations A * X = B.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> Arguments
</span><span class="comment">*</span><span class="comment"> =========
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> N (input) INTEGER
</span><span class="comment">*</span><span class="comment"> The number of linear equations, i.e., the order of the
</span><span class="comment">*</span><span class="comment"> matrix A. N >= 0.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> NRHS (input) INTEGER
</span><span class="comment">*</span><span class="comment"> The number of right hand sides, i.e., the number of columns
</span><span class="comment">*</span><span class="comment"> of the matrix B. NRHS >= 0.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> A (input/output) COMPLEX*16 array, dimension (LDA,N)
</span><span class="comment">*</span><span class="comment"> On entry, the N-by-N coefficient matrix A.
</span><span class="comment">*</span><span class="comment"> On exit, the factors L and U from the factorization
</span><span class="comment">*</span><span class="comment"> A = P*L*U; the unit diagonal elements of L are not stored.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> LDA (input) INTEGER
</span><span class="comment">*</span><span class="comment"> The leading dimension of the array A. LDA >= max(1,N).
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> IPIV (output) INTEGER array, dimension (N)
</span><span class="comment">*</span><span class="comment"> The pivot indices that define the permutation matrix P;
</span><span class="comment">*</span><span class="comment"> row i of the matrix was interchanged with row IPIV(i).
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> B (input/output) COMPLEX*16 array, dimension (LDB,NRHS)
</span><span class="comment">*</span><span class="comment"> On entry, the N-by-NRHS matrix of right hand side matrix B.
</span><span class="comment">*</span><span class="comment"> On exit, if INFO = 0, the N-by-NRHS solution matrix X.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> LDB (input) INTEGER
</span><span class="comment">*</span><span class="comment"> The leading dimension of the array B. LDB >= max(1,N).
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> INFO (output) INTEGER
</span><span class="comment">*</span><span class="comment"> = 0: successful exit
</span><span class="comment">*</span><span class="comment"> < 0: if INFO = -i, the i-th argument had an illegal value
</span><span class="comment">*</span><span class="comment"> > 0: if INFO = i, U(i,i) is exactly zero. The factorization
</span><span class="comment">*</span><span class="comment"> has been completed, but the factor U is exactly
</span><span class="comment">*</span><span class="comment"> singular, so the solution could not be computed.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> =====================================================================
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> .. External Subroutines ..
</span> EXTERNAL <a name="XERBLA.69"></a><a href="xerbla.f.html#XERBLA.1">XERBLA</a>, <a name="ZGETRF.69"></a><a href="zgetrf.f.html#ZGETRF.1">ZGETRF</a>, <a name="ZGETRS.69"></a><a href="zgetrs.f.html#ZGETRS.1">ZGETRS</a>
<span class="comment">*</span><span class="comment"> ..
</span><span class="comment">*</span><span class="comment"> .. Intrinsic Functions ..
</span> INTRINSIC MAX
<span class="comment">*</span><span class="comment"> ..
</span><span class="comment">*</span><span class="comment"> .. Executable Statements ..
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> Test the input parameters.
</span><span class="comment">*</span><span class="comment">
</span> INFO = 0
IF( N.LT.0 ) THEN
INFO = -1
ELSE IF( NRHS.LT.0 ) THEN
INFO = -2
ELSE IF( LDA.LT.MAX( 1, N ) ) THEN
INFO = -4
ELSE IF( LDB.LT.MAX( 1, N ) ) THEN
INFO = -7
END IF
IF( INFO.NE.0 ) THEN
CALL <a name="XERBLA.89"></a><a href="xerbla.f.html#XERBLA.1">XERBLA</a>( <span class="string">'<a name="ZGESV.89"></a><a href="zgesv.f.html#ZGESV.1">ZGESV</a> '</span>, -INFO )
RETURN
END IF
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> Compute the LU factorization of A.
</span><span class="comment">*</span><span class="comment">
</span> CALL <a name="ZGETRF.95"></a><a href="zgetrf.f.html#ZGETRF.1">ZGETRF</a>( N, N, A, LDA, IPIV, INFO )
IF( INFO.EQ.0 ) THEN
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> Solve the system A*X = B, overwriting B with X.
</span><span class="comment">*</span><span class="comment">
</span> CALL <a name="ZGETRS.100"></a><a href="zgetrs.f.html#ZGETRS.1">ZGETRS</a>( <span class="string">'No transpose'</span>, N, NRHS, A, LDA, IPIV, B, LDB,
$ INFO )
END IF
RETURN
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> End of <a name="ZGESV.105"></a><a href="zgesv.f.html#ZGESV.1">ZGESV</a>
</span><span class="comment">*</span><span class="comment">
</span> END
</pre>
</body>
</html>
⌨️ 快捷键说明
复制代码Ctrl + C
搜索代码Ctrl + F
全屏模式F11
增大字号Ctrl + =
减小字号Ctrl + -
显示快捷键?