Visible to Intel only — GUID: GUID-9231C409-4327-4670-A557-98D1318CA2FC
Visible to Intel only — GUID: GUID-9231C409-4327-4670-A557-98D1318CA2FC
?syconv
Converts a symmetric matrix given by a triangular matrix factorization into two matrices and vice versa.
Syntax
call ssyconv( uplo, way, n, a, lda, ipiv, e, info )
call dsyconv( uplo, way, n, a, lda, ipiv, e, info )
call csyconv( uplo, way, n, a, lda, ipiv, e, info )
call zsyconv( uplo, way, n, a, lda, ipiv, e, info )
call syconv( a[,uplo][,way][,ipiv][,info][,e] )
Include Files
- mkl.fi, lapack.f90
Description
The routine converts matrix A, which results from a triangular matrix factorization, into matrices L and D and vice versa. The routine returns non-diagonalized elements of D and applies or reverses permutation done with the triangular matrix factorization.
Input Parameters
- uplo
-
CHARACTER*1. Must be 'U' or 'L'.
Indicates whether the details of the factorization are stored as an upper or lower triangular matrix:
If uplo = 'U': the upper triangular, A = U*D*UT.
If uplo = 'L': the lower triangular, A = L*D*LT.
- way
-
CHARACTER*1. Must be 'C' or 'R'.
- n
-
INTEGER. The order of matrix A; n≥ 0.
- a
-
REAL for ssyconv
DOUBLE PRECISION for dsyconv
COMPLEX for csyconv
DOUBLE COMPLEX for zsyconv
Array of size lda by n.
The block diagonal matrix D and the multipliers used to obtain the factor U or L as computed by ?sytrf.
- lda
-
INTEGER. The leading dimension of a; lda≥ max(1, n).
- ipiv
-
INTEGER. Array, size at least max(1, n).
Details of the interchanges and the block structure of D, as returned by ?sytrf.
Output Parameters
- e
-
REAL for ssyconv
DOUBLE PRECISION for dsyconv
COMPLEX for csyconv
DOUBLE COMPLEX for zsyconv
Array of size max(1, n) containing the superdiagonal/subdiagonal of the symmetric 1-by-1 or 2-by-2 block diagonal matrix D in L*D*LT.
- info
-
INTEGER. If info = 0, the execution is successful.
If info < 0, the i-th parameter had an illegal value.
If info = -1011, memory allocation error occurred.
LAPACK 95 Interface Notes
Routines in Fortran 95 interface have fewer arguments in the calling sequence than their FORTRAN 77 counterparts. For general conventions applied to skip redundant or reconstructible arguments, see LAPACK 95 Interface Conventions.
Specific details for the routine syconv interface are as follows:
a |
Holds the matrix A of size (n, n). |
uplo |
Must be 'U' or 'L'. |
way |
Must be 'C' or 'R'. |
ipiv |
Holds the vector of length n. |
e |
Holds the vector of length n. |