UPLO
UPLO is CHARACTER*1
Specifies whether the details of the factorization are stored
as an upper or lower triangular matrix.
= 'U': Upper triangular, form is A = U*D*U**T;
= 'L': Lower triangular, form is A = L*D*L**T.
N
N is INTEGER
The order of the matrix A. N >= 0.
A
A is COMPLEX*16 array, dimension (LDA,*)
On entry, the N-by-N matrix A. On exit, the permuted matrix
where the rows I1 and I2 and columns I1 and I2 are interchanged.
If UPLO = 'U', the interchanges are applied to the upper
triangular part and the strictly lower triangular part of A is
not referenced; if UPLO = 'L', the interchanges are applied to
the lower triangular part and the part of A above the diagonal
is not referenced.
LDA
LDA is INTEGER
The leading dimension of the array A. LDA >= max(1,N).
I1
I1 is INTEGER
Index of the first row to swap
I2
I2 is INTEGER
Index of the second row to swap