debian man page for zppequ

zppequ.f(3)							      LAPACK							       zppequ.f(3)

NAME
       zppequ.f -

SYNOPSIS
   Functions/Subroutines
       subroutine zppequ (UPLO, N, AP, S, SCOND, AMAX, INFO)
	   ZPPEQU

Function/Subroutine Documentation
   subroutine zppequ (characterUPLO, integerN, complex*16, dimension( * )AP, double precision, dimension( * )S, double precisionSCOND, double
       precisionAMAX, integerINFO)
       ZPPEQU

       Purpose:

	    ZPPEQU computes row and column scalings intended to equilibrate a
	    Hermitian positive definite matrix A in packed storage and reduce
	    its condition number (with respect to the two-norm).  S contains the
	    scale factors, S(i)=1/sqrt(A(i,i)), chosen so that the scaled matrix
	    B with elements B(i,j)=S(i)*A(i,j)*S(j) has ones on the diagonal.
	    This choice of S puts the condition number of B within a factor N of
	    the smallest possible condition number over all possible diagonal
	    scalings.

       Parameters:
	   UPLO

		     UPLO is CHARACTER*1
		     = 'U':  Upper triangle of A is stored;
		     = 'L':  Lower triangle of A is stored.

	   N

		     N is INTEGER
		     The order of the matrix A.  N >= 0.

	   AP

		     AP is COMPLEX*16 array, dimension (N*(N+1)/2)
		     The upper or lower triangle of the Hermitian matrix A, packed
		     columnwise in a linear array.  The j-th column of A is stored
		     in the array AP as follows:
		     if UPLO = 'U', AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j;
		     if UPLO = 'L', AP(i + (j-1)*(2n-j)/2) = A(i,j) for j<=i<=n.

	   S

		     S is DOUBLE PRECISION array, dimension (N)
		     If INFO = 0, S contains the scale factors for A.

	   SCOND

		     SCOND is DOUBLE PRECISION
		     If INFO = 0, S contains the ratio of the smallest S(i) to
		     the largest S(i).	If SCOND >= 0.1 and AMAX is neither too
		     large nor too small, it is not worth scaling by S.

	   AMAX

		     AMAX is DOUBLE PRECISION
		     Absolute value of largest matrix element.	If AMAX is very
		     close to overflow or very close to underflow, the matrix
		     should be scaled.

	   INFO

		     INFO is 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 is nonpositive.

       Author:
	   Univ. of Tennessee

	   Univ. of California Berkeley

	   Univ. of Colorado Denver

	   NAG Ltd.

       Date:
	   November 2011

       Definition at line 118 of file zppequ.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

Version 3.4.1							  Sun May 26 2013						       zppequ.f(3)