ztrtrs(l) [redhat man page]

ZTRTRS(l)								 )								 ZTRTRS(l)

NAME

       ZTRTRS - solve a triangular system of the form  A * X = B, A**T * X = B, or A**H * X = B,

SYNOPSIS

       SUBROUTINE ZTRTRS( UPLO, TRANS, DIAG, N, NRHS, A, LDA, B, LDB, INFO )

	   CHARACTER	  DIAG, TRANS, UPLO

	   INTEGER	  INFO, LDA, LDB, N, NRHS

	   COMPLEX*16	  A( LDA, * ), B( LDB, * )

PURPOSE

       ZTRTRS solves a triangular system of the form A * X = B, A**T * X = B, or A**H * X = B, where A is a triangular matrix of order N, and B is
       an N-by-NRHS matrix.  A check is made to verify that A is nonsingular.

ARGUMENTS

       UPLO    (input) CHARACTER*1
	       = 'U':  A is upper triangular;
	       = 'L':  A is lower triangular.

       TRANS   (input) CHARACTER*1
	       Specifies the form of the system of equations:
	       = 'N':  A * X = B     (No transpose)
	       = 'T':  A**T * X = B  (Transpose)
	       = 'C':  A**H * X = B  (Conjugate transpose)

       DIAG    (input) CHARACTER*1
	       = 'N':  A is non-unit triangular;
	       = 'U':  A is unit triangular.

       N       (input) INTEGER
	       The order of the matrix A.  N >= 0.

       NRHS    (input) INTEGER
	       The number of right hand sides, i.e., the number of columns of the matrix B.  NRHS >= 0.

       A       (input) COMPLEX*16 array, dimension (LDA,N)
	       The triangular matrix A.  If UPLO = 'U', the leading N-by-N upper triangular part of the array  A  contains  the  upper	triangular
	       matrix,	and the strictly lower triangular part of A is not referenced.	If UPLO = 'L', the leading N-by-N lower triangular part of
	       the array A contains the lower triangular matrix, and the strictly upper triangular part of A is not referenced.  If  DIAG  =  'U',
	       the diagonal elements of A are also not referenced and are assumed to be 1.

       LDA     (input) INTEGER
	       The leading dimension of the array A.  LDA >= max(1,N).

       B       (input/output) COMPLEX*16 array, dimension (LDB,NRHS)
	       On entry, the right hand side matrix B.	On exit, if INFO = 0, the solution matrix X.

       LDB     (input) INTEGER
	       The leading dimension of the array B.  LDB >= max(1,N).

       INFO    (output) INTEGER
	       = 0:  successful exit
	       < 0: if INFO = -i, the i-th argument had an illegal value
	       >  0: if INFO = i, the i-th diagonal element of A is zero, indicating that the matrix is singular and the solutions X have not been
	       computed.

LAPACK version 3.0						   15 June 2000 							 ZTRTRS(l)

Check Out this Related Man Page

ZTPTRS(l)								 )								 ZTPTRS(l)

NAME

       ZTPTRS - solve a triangular system of the form  A * X = B, A**T * X = B, or A**H * X = B,

SYNOPSIS

       SUBROUTINE ZTPTRS( UPLO, TRANS, DIAG, N, NRHS, AP, B, LDB, INFO )

	   CHARACTER	  DIAG, TRANS, UPLO

	   INTEGER	  INFO, LDB, N, NRHS

	   COMPLEX*16	  AP( * ), B( LDB, * )

PURPOSE

       ZTPTRS solves a triangular system of the form A * X = B, A**T * X = B, or A**H * X = B, where A is a triangular matrix of order N stored in
       packed format, and B is an N-by-NRHS matrix.  A check is made to verify that A is nonsingular.

ARGUMENTS

       UPLO    (input) CHARACTER*1
	       = 'U':  A is upper triangular;
	       = 'L':  A is lower triangular.

       TRANS   (input) CHARACTER*1
	       Specifies the form of the system of equations:
	       = 'N':  A * X = B     (No transpose)
	       = 'T':  A**T * X = B  (Transpose)
	       = 'C':  A**H * X = B  (Conjugate transpose)

       DIAG    (input) CHARACTER*1
	       = 'N':  A is non-unit triangular;
	       = 'U':  A is unit triangular.

       N       (input) INTEGER
	       The order of the matrix A.  N >= 0.

       NRHS    (input) INTEGER
	       The number of right hand sides, i.e., the number of columns of the matrix B.  NRHS >= 0.

       AP      (input) COMPLEX*16 array, dimension (N*(N+1)/2)
	       The upper or lower triangular matrix A, packed columnwise in a linear array.  The j-th column of A is stored in	the  array  AP	as
	       follows: if UPLO = 'U', AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j; if UPLO = 'L', AP(i + (j-1)*(2*n-j)/2) = A(i,j) for j<=i<=n.

       B       (input/output) COMPLEX*16 array, dimension (LDB,NRHS)
	       On entry, the right hand side matrix B.	On exit, if INFO = 0, the solution matrix X.

       LDB     (input) INTEGER
	       The leading dimension of the array B.  LDB >= max(1,N).

       INFO    (output) INTEGER
	       = 0:  successful exit
	       < 0:  if INFO = -i, the i-th argument had an illegal value
	       > 0:  if INFO = i, the i-th diagonal element of A is zero, indicating that the matrix is singular and the solutions X have not been
	       computed.

LAPACK version 3.0						   15 June 2000 							 ZTPTRS(l)

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ztrtrs(l) [redhat man page]

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