DSYSWAPR applies an elementary permutation on the rows and the columns of


 a symmetric matrix.

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 DOUBLE PRECISION 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

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