org.netlib.lapack
Class Sgbequ

java.lang.Object
  org.netlib.lapack.Sgbequ

public class Sgbequ
extends java.lang.Object

Following is the description from the original
Fortran source.  For each array argument, the Java
version will include an integer offset parameter, so
the arguments may not match the description exactly.
Contact seymour@cs.utk.edu with any questions.


 *     ..
 *
 *  Purpose
 *  =======
 *
 *  SGBEQU computes row and column scalings intended to equilibrate an
 *  M-by-N band matrix A and reduce its condition number.  R returns the

 *  row scale factors and C the column scale factors, chosen to try to
 *  make the largest element in each row and column of the matrix B with

 *  elements B(i,j)=R(i)*A(i,j)*C(j) have absolute value 1.
 *
 *  R(i) and C(j) are restricted to be between SMLNUM = smallest safe
 *  number and BIGNUM = largest safe number.  Use of these scaling
 *  factors is not guaranteed to reduce the condition number of A but
 *  works well in practice.
 *
 *  Arguments
 *  =========
 *
 *  M       (input) INTEGER
 *          The number of rows of the matrix A.  M >= 0.
 *
 *  N       (input) INTEGER
 *          The number of columns of the matrix A.  N >= 0.
 *
 *  KL      (input) INTEGER
 *          The number of subdiagonals within the band of A.  KL >= 0.
 *
 *  KU      (input) INTEGER
 *          The number of superdiagonals within the band of A.  KU >= 0.

 *
 *  AB      (input) REAL array, dimension (LDAB,N)
 *          The band matrix A, stored in rows 1 to KL+KU+1.  The j-th
 *          column of A is stored in the j-th column of the array AB as
 *          follows:
 *          AB(ku+1+i-j,j) = A(i,j) for max(1,j-ku)<=i<=min(m,j+kl).
 *
 *  LDAB    (input) INTEGER
 *          The leading dimension of the array AB.  LDAB >= KL+KU+1.
 *
 *  R       (output) REAL array, dimension (M)
 *          If INFO = 0, or INFO > M, R contains the row scale factors
 *          for A.
 *
 *  C       (output) REAL array, dimension (N)
 *          If INFO = 0, C contains the column scale factors for A.
 *
 *  ROWCND  (output) REAL
 *          If INFO = 0 or INFO > M, ROWCND contains the ratio of the
 *          smallest R(i) to the largest R(i).  If ROWCND >= 0.1 and
 *          AMAX is neither too large nor too small, it is not worth
 *          scaling by R.
 *
 *  COLCND  (output) REAL
 *          If INFO = 0, COLCND contains the ratio of the smallest
 *          C(i) to the largest C(i).  If COLCND >= 0.1, it is not
 *          worth scaling by C.
 *
 *  AMAX    (output) REAL
 *          Absolute value of largest matrix element.  If AMAX is very
 *          close to overflow or very close to underflow, the matrix
 *          should be scaled.
 *
 *  INFO    (output) INTEGER
 *          = 0:  successful exit
 *          < 0:  if INFO = -i, the i-th argument had an illegal value
 *          > 0:  if INFO = i, and i is
 *                <= M:  the i-th row of A is exactly zero
 *                >  M:  the (i-M)-th column of A is exactly zero
 *
 *  =====================================================================
 *
 *     .. Parameters ..

Constructor Summary

Sgbequ()

Method Summary

static void

sgbequ(int m, int n, int kl, int ku, float[] ab, int _ab_offset, int ldab, float[] r, int _r_offset, float[] c, int _c_offset, floatW rowcnd, floatW colcnd, floatW amax, intW info)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Sgbequ

public Sgbequ()

Method Detail

sgbequ

public static void sgbequ(int m,
                          int n,
                          int kl,
                          int ku,
                          float[] ab,
                          int _ab_offset,
                          int ldab,
                          float[] r,
                          int _r_offset,
                          float[] c,
                          int _c_offset,
                          floatW rowcnd,
                          floatW colcnd,
                          floatW amax,
                          intW info)