ctptrs (l) - Linux Man Pages
ctptrs: solves a triangular system of the form A * X = B, A**T * X = B, or A**H * X = B,
Command to display
ctptrs manual in Linux:
$ man l ctptrs
CTPTRS - solves a triangular system of the form A * X = B, A**T * X = B, or A**H * X = B,
- SUBROUTINE CTPTRS(
UPLO, TRANS, DIAG, N, NRHS, AP, B, LDB, INFO )
DIAG, TRANS, UPLO
INFO, LDB, N, NRHS
AP( * ), B( LDB, * )
CTPTRS solves a triangular system of the form
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
- UPLO (input) CHARACTER*1
= aqUaq: A is upper triangular;
= aqLaq: A is lower triangular.
- TRANS (input) CHARACTER*1
Specifies the form of the system of equations:
= aqNaq: A * X = B (No transpose)
= aqTaq: A**T * X = B (Transpose)
= aqCaq: A**H * X = B (Conjugate transpose)
- DIAG (input) CHARACTER*1
= aqNaq: A is non-unit triangular;
= aqUaq: 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 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 = aqUaq, AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j;
if UPLO = aqLaq, AP(i + (j-1)*(2*n-j)/2) = A(i,j) for j<=i<=n.
- B (input/output) COMPLEX 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.
Pages related to ctptrs
- ctptrs (3)
- ctptri (l) - computes the inverse of a complex upper or lower triangular matrix A stored in packed format
- ctpttf (l) - copies a triangular matrix A from standard packed format (TP) to rectangular full packed format (TF)
- ctpttr (l) - copies a triangular matrix A from standard packed format (TP) to standard full format (TR)
- ctpcon (l) - estimates the reciprocal of the condition number of a packed triangular matrix A, in either the 1-norm or the infinity-norm
- ctpmv (l) - performs one of the matrix-vector operations x := A*x, or x := Aaq*x, or x := conjg( Aaq )*x,
- ctprfs (l) - provides error bounds and backward error estimates for the solution to a system of linear equations with a triangular packed coefficient matrix
- ctpsv (l) - solves one of the systems of equations A*x = b, or Aaq*x = b, or conjg( Aaq )*x = b,