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Visible to Intel only — GUID: GUID-C5A66DAD-6049-4E9F-9108-9BF0E7C9B23E
?syswapr1
Applies an elementary permutation on the rows and columns of a symmetric matrix.
Syntax
call ssyswapr1( uplo, n, a, lda, i1, i2 )
call dsyswapr1( uplo, n, a, lda, i1, i2 )
call csyswapr1( uplo, n, a, lda, i1, i2 )
call zsyswapr1( uplo, n, a, lda, i1, i2 )
call syswapr1( a,i1,i2[,uplo] )
Include Files
- mkl.fi, lapack.f90
Description
The routine applies an elementary permutation on the rows and columns of a symmetric matrix.
Input Parameters
- uplo
-
CHARACTER*1. Must be 'U' or 'L'.
Indicates how the input matrix A has been factored:
If uplo = 'U', the array a stores the upper triangular factor U of the factorization A = U*D*UT.
If uplo = 'L', the array a stores the lower triangular factor L of the factorization A = L*D*LT.
- n
-
INTEGER. The order of matrix A; n≥ 0.
- nrhs
-
INTEGER. The number of right-hand sides; nrhs≥ 0.
- a
-
REAL for ssyswapr1
DOUBLE PRECISION for dsyswapr1
COMPLEX for csyswapr1
DOUBLE COMPLEX for zsyswapr1
Array of dimension (lda,n).
The array a contains 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 the array a. lda≥max(1,n).
- i1
-
INTEGER. Index of the first row to swap.
- i2
-
INTEGER. Index of the second row to swap.
Output Parameters
- a
-
If info = 0, the symmetric inverse of the original matrix.
If info = 'U', the upper triangular part of the inverse is formed and the part of A below the diagonal is not referenced.
If info = 'L', the lower triangular part of the inverse is formed and the part of A above the diagonal is not referenced.
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 syswapr1 interface are as follows:
- a
-
Holds the matrix A of size (n, n).
- i1
-
Holds the index for swap.
- i2
-
Holds the index for swap.
- uplo
-
Indicates how the matrix A has been factored. Must be 'U' or 'L'.