org.netlib.lapack
Class Sgeequ

java.lang.Object
  org.netlib.lapack.Sgeequ

public class Sgeequ
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
 *  =======
 *
 *  SGEEQU computes row and column scalings intended to equilibrate an
 *  M-by-N 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.
 *
 *  A       (input) REAL array, dimension (LDA,N)
 *          The M-by-N matrix whose equilibration factors are
 *          to be computed.
 *
 *  LDA     (input) INTEGER
 *          The leading dimension of the array A.  LDA >= max(1,M).
 *
 *  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

Sgeequ()

Method Summary

static void

sgeequ(int m, int n, float[] a, int _a_offset, int lda, 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

Sgeequ

public Sgeequ()

Method Detail

sgeequ

public static void sgeequ(int m,
                          int n,
                          float[] a,
                          int _a_offset,
                          int lda,
                          float[] r,
                          int _r_offset,
                          float[] c,
                          int _c_offset,
                          floatW rowcnd,
                          floatW colcnd,
                          floatW amax,
                          intW info)